Read the sticky by Cory on the Thunderbolt hacking forum for tips like the one mclarryjr gave before doing anything. The post also keeps a list of which apks and odexes are safe to move/rename.
That being said, you would need Root Explorer or adb/terminal emulator to be able to move or rename the files (don't delete just yet) so thy don't get loaded by the OS. If you are using adb or terminal you will need to prefix most of your commands with the busybox binary.