Downgrading iTunes for Mac

Hello everyone

i accidently updated 7.4 and now couple of buttons are screwed up ( caused to theming) so now i reinstalled 7.2. Couldn't start

Error: The file "iTunes Library" cannot be read because it was created by a newer version of iTunes

Can someone tell me where & how could i remove it or any way i could start the version 7.2

much appreciated, thanks