From Yosemite to Mavericks

I originally bought my Mac mini on Yosemite. I wanted to downgrade to mavericks, and on this website I read that if I went into core services and changed my SystemVersion.plist from 10.10 to 10.8 and download Mavericks from the AppStore, I would have mavericks. Guess what? App Store doesn't even work! All of my apple apps don't work because it says I need 10.10, including text edit. Can someone please help me? I even called apple and they didn't know what to do. HELP!!!!