Yosemite - Pre-release: How do I opt out installing the beta seed?

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!

It seems to be an App Store preference.

https://appleseed.apple.com/sp/betaprogram/unenroll

Go to System Preference -> App Store, then select Stop showing pre-release Software Update seeds in the App Store

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