Last night Apple put forth 14B17 a Pre-release: OS X Update Seed 10.10.1
I don't want to install it, but it doesn't go away.
I tried downloading the 'normal' Yosemite from the App Store and reinstalled it over the old one. All is well but the Pre-release update is still there bugging me to upgrade.
How do I disable it? There should be a file somewhere that survives a OS X reinstall (in place upgrade) but I can't figure out where.
Later edit... You're right. However my Change button had no text in it and it was small. I think this is a localization issue/bug. Change to English and there it was. Thanks!