To be safe.. go to C:\program files\RugbyLeague\data and copy the DB, MAESTRO, MOVIE, WORLD and TEAM folders.
Copy them and store them in another location outside of your rugby league folder. Timmos patch will overwrite certain files in those folders automatically. After you install Timmos patch, if you like everything about the patch leave everything as it is.
But if you don't like the new movie for example.. copy the backed up folder for movie, the one you stored somewhere else and replace the new movie folder with your old one. It's a lot easier doing this, rather then reinstalling your whole game again.
Edit- Your going to love Timmos logos and jerseys.