Anyone know how to remove this update and just play the vanilla version?
The Community Update hasn't been properly incorporated into the game yet. So far, the only changes that do apply are that the icons for food bonus tiles on planets are no longer shown, that you can no longer get planets via diplomacy from other races, and some other minor UI changes. If you want, I can upload the necessary files to revert those changes.
Once the CU has been properly incorporated, however, it won't be possible to play the vanilla version anymore. The next best thing will be my mod, Autumn Twilight, which contains all the bugfixes of the CU, but keeps the gameplay as close as possible to the vanilla one.