Taken from Gamefront: This is patch 1.03 for the game. Warning this is not the latest version of the game if you want the latest version download patch v1.04
Finally the 1.03 patch for JK2 has been released! Included are many fixes to the game, mostly multi player ones.
There are also 4 new MP Duel maps included! Here is a list of *some* of the fixes in MP:
And much more! (all fixes/addons are in the readme) Obviously, a must download ;):p
Note: You will not be able to join servers who are running the original 1.2 version, the server HAS to run 1.3 in order for you to play on it.
The MP light saber stances have been changed somewhat, for the good or bad is up to you to decide.
Uninstall: The only way (according to me) is to reinstall the game itself.
If you do reinstall, make sure you backup whatever you put in the "base" folder in terms of skins/maps/cfg's, etc. because it will get wiped out (do not backup the assets#.pk3's just the custom files).