Catholics of any Church, Latin, Eastern, or Oriental may request a "Change of Canonical Enrollment" (the formal name for the process of translating from one Particular Church to another). The process is essentially as described by Schultz, although "sitting on the petition" is no longer acceptable and expedient action on it is to be expected (and can be enforced by recourse to proper authority). That does not mean that all such petitions are granted.
The length of time involved in the process can vary significantly. The authority to approve such a Change is formally delegated to the discretion of the ordinaries involved (the bishop or eparch of the local diocese/ eparchy of the Church from which the petitioner is originating and his counterpart of the Church to which the petitioner seeks to join).
In brief, the process begins when a person believes that his or her spiritual well-being would best be served by fully participating in the life of a sui iuris Church other than the one of which he or she is then a member. How soon after becoming acquainted with another Church sui iuris can one legitimately claim such discernment? It varies from individual to individual, but some jurisdictions have quantified it from their perspective, formally requiring participation by the petitioner in the life of one of their parishes for anywhere from 1 to 3 years before approval will be granted. I think it's safe to say that, on the whole, a minimum of two years should/would be expected.
The petitioner addresses the request to both his/her existing ordinary and the ordinary into whose jurisdiction he/she seeks to transfer, explaining the motivation for seeking to change. (When a change is sought for the express purpose of pursuing the Mystery of Holy Orders, the approval to grant such Change is ordinarily reserved to the Sacred Congregation for the Oriental Church. This is intended to assure that such is not done merely to bypass the Latin Church's discipline against married clergy.)
Most movement is from West to East and there is a decided prejudice on the part of both Latin and Eastern hierarchs against changes that are motivated by dissatisfaction with the liturgical praxis of the Latin Church. While we of the Eastern and Oriental Catholic Churches appreciate interest in us and in our liturgical traditions, we want to and must be understood and appreciated for ourselves, not as an antidote to what disaffected Latins perceive as wrong in their own Church. The Novus Ordo Mass is neither less authentic nor holy than the Tridentine Mass; each, as a service of worship directed to God, has its own intrinsic holiness when served faithfully and reverently. To the extent that abuses exist within either, they must needs be addressed; but the form is only that - an external; ultimately, worship comes from within oneself, one's heart and soul. Petitions espousing traditionalist viewpoints that result in an antagonistic view toward the Novus Ordo and post-Vatican II reforms are not ordinarily deemed an appropriate basis for granting Change. Why? Among other reasons are the fact that the Eastern or Oriental Catholic Church one sees today may not be the one of tomorrow, as our Churches undergo their own reforms, intended to remove latinizations and restore our own traditions.
The extent to which one might potentially encounter this kind of situation (disenchantment with one's new liturgical environment) will vary. Some Eastern and Oriental Churches are much further along in achieving a return to their historical liturgical origins than others - so, to use a computer analogy, WYSIWYG (What You See Is What You Get). In others, what you see may not be what you'll ultimately have. Even within Churches, there are differences in how far along parishes are in doing so. Will a transplanted Latin still like us when we look less like the Church they've romanticized us to be? Or will they be disenchanted and want to move on? And to where? In most instances, as several have indicated, only a single Change of Canonical Enrollment is permitted, although there is presently no canonical provision to that effect and it is speculative whether it would be enforced across the board (under earlier Canon Law, there was a provision to this effect).
In assessing the motivation for a requested change, one consideration on the part of the both hierarchs (especially the one who is being asked to receive the petitioner) is the extent to which it is perceived that the petitioner truly understands and is drawn to the Church for reasons related to his/her theological development and spiritual well-being.
The prevailing view is that a Change of Canonical Enrollment is a decision that should not be lightly made. For many, it is not only a change of parish and rite, but also a whole process of inculturation, particularly given the ethnicity of our parishes. We tend to be a 'family' and 'family' is more than liking the pirohi, the fataya, or the lahmajun at the annual food fair weekend. Anyone intending to make a change should feel certain that they feel comfortable not only with the spirituality, but with the community with whom they will share and explore and develop that spirituality. They are often entering into a community whose ties to one another stretch back generations - sometimes back to a single village in the Levant, the Ukraine, or elsewhere. Our parishes are either very welcoming to outsiders who come among us or incredibly closed - there is no in-between. And we do need to be welcoming - assimilation and a ghetto mentality may be opposite ends of a continuum, but
they both represent a real danger to the continued viability of our Churches.
Under the now abrogated 1917 Code of Canon LAw, converts to Catholicism were to be accepted into the Church which was "most akin" to the convert's religion of origin. This meant that Proterstants would convert to the Latin Church and Orthodox would convert to the most appropriate Eastern or Oriental Catholic Church. That provision has been removed from the current Latin and Eastern Codes, which now provide:
-Ãƒâ€šÃ‚Âº1 Through the reception of baptism a child becomes a member of the Latin Church if the parents belong to that Church or, should one of them not belong to it, if they have both by common consent chosen that the child be baptised in the Latin Church: if that common consent is lacking, the child becomes a member of the ritual Church to which the father belongs.
-Ãƒâ€šÃ‚Âº2 Any candidate for baptism who has completed the fourteenth year of age may freely choose to be baptised either in the Latin Church or in another autonomous ritual Church; in which case the person belongs to the Church which he or she has chosen.
-Ãƒâ€šÃ‚Âº1 Persons who desire to join the Church are to be admitted with liturgical ceremonies to the catechumenate, which is not a mere presentation of teachings and precepts, but a formation in all the Christian life and an apprenticeship duly lasting for sometime.
Catechumens are free to enroll in whatever Church sui iuris they want, according to the norm of Canon 30; however, it has to be provided that nothing stands in the way of their enrollment in the Church that is more appropriate to their culture.
Anyone to be baptized who has completed the fourteenth year of age can freely select any Church sui iuris in which he or she then is enrolled by virtue of baptism received in that same Church, with due regard for particular law established by the Apostolic See.
No one can presume in any way to induce the Christian faithful to transfer to another Church sui iuris.
As to marriage and children, according to the Eastern Code:
A wife is at liberty to transfer to the Church of the husband at the celebration of or during the marriage; when the marriage has ended, she can freely return to the original Church sui iuris.
If the parents, or the Catholic spouse in the case of a mixed marriage, transfer to another Church sui iuris, children under fourteen years old by the law itself are enrolled in the same Church; if in a marriage of Catholics only one parent transfers to another Church sui iuris, the children transfer only if both parents consent. Upon completion of the fourteenth year of age, the children can return to the original Church sui iuris.