Reinstall Mountain Lion on an older mac

Solution 1:

I just saw this article this morning that might be helpful: How to Prepare a MacBook Pro For Sale that was Upgraded to Mavericks by Scott Williams

Solution 2:

As to whether the Apple ID persists on the reinstalled drive using the approach I did: I don't know.

A better way is probably to install Mavericks from a USB thumb drive, described here:

http://forums.macrumors.com/showpost.php?p=18081307&postcount=3

sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ Mavericks.app --nointeraction

Assuming "Install OS X Mavericks.app" is in your Applications folder and your thumbdrive is called "Untitled".