thanks for the replies y'all.
it's a macOS X 10.5. 8 that's as much as I can say now
Really, then you uninstalling Firefox should be as easy as simply dragging its icon in the application fold to the trashcan.
This will delete most of the files associated with the program.
Looking over mozilla's website, it looks like they don't want to support any of their legacy browsers which would have worked on OS X 10.5.x.
Arguably the best OS X 10 version is 10.6.8. It should run on your machine; it is the most stable version to date and many people like myself have avoided 10.7, 10.8, and likely 10.9 due to some odd choices made by Apple regarding how they are managed their desktop OS.
If you don't want to upgrade to 10.6.8. It costs $20 basically. You could work around mozilla's attempts to protect you from yourself, see option 3 here:https://support.mozilla.org/en-US/kb/firefox-no-longer-works-mac-os-x-10-5
If you would like any help with your options whether upgrading or otherwise, let me know.
Based on your model, it is 99% likely that your machine will run much faster with 10.6.8.