I've recently upgraded to Mac OS Yosemite, but the App Store won't let me install app updates. It says "Sign in to the App Store to download apps." I'm already signed in though, and the sign in box that pops up won't let me change the Apple ID to mine. I've restarted, logged out, logged in again, and it still won't work. I'd assume that this is because they were installed with a different Apple ID. Can I uninstall and reinstall the apps without buying them/losing data? Will installing the apps myself again without updating get the updates and stop telling me about them? Or is there any way to install these updates? Also, they're for the Apple apps like iPhoto, iMovie, and GarageBand, but nothing other than those Apple ones.