Re: Uninstalling an expansion pack in Sims 3 64-bit
@Elowi Wherever your Sims 3 base game is installed, there should also be a "The Sims 3 Packs" folder. Open that folder, find the pack you want to uninstall on the list, and delete it. Packs are listed by type and release order, e.g. World Adventures was the first expansion pack released, so its folder is EP01.
You shouldn't need to do anything else. I've tested deleting a pack this way, and the game worked fine. The caveat of course is that a save exposed to the pack you uninstall may be corrupted beyond repair if you load it with that pack no longer present. (This should only be an issue with expansions, not stuff packs.) But this is a problem no matter how you uninstall the pack.
Please let me know if you get an error after uninstalling a pack this way though; I'd like to know if there are any issues I didn't see myself.