Keep in mind there are two different things to install:
(1) The Panda3D plugin. This is the only part that might complain about a newer version already existing. If it does complain, it just means that you already have it installed, and there’s no need to install a new one. This is good, because the operating system does make it difficult to reinstall this. It’s possible, though, if you’re really determined.
(2) The Toontown game. (Re)installing this has absolutely nothing to do with (Re)installing the Panda3D plugin, above. If you are having problems with the game, reinstalling the plugin probably won’t help you solve them, but reinstalling the game might, depending on the nature of the problem. Fortunately, it is easy to reinstall this part.
Now, as to what problem you are actually having, I can’t tell you whether it should be solved by reinstalling (1) or (2) without knowing more details about the problem. It’s quite likely that even if we successfully walked through the steps to reinstall (1), nothing at all would change and you would still have the same problem.
So, can you give me more information about the way in which Toontown is failing to load?
David