iMac Stolen, recovered, passwords changed
My iMac 27 was stolen and then recovered. The thieves added a new admin account "User" that has no password. My accounts are visible, but the passwords I was using when they stole it are no longer valid. I thought I could simply use the new "User" admin account to access Users & Groups and reset my account passwords. But when I go to Users & Groups my old accounts are greyed out, I cannot select them.
How can I regain access to my original accounts?
iMac, Mac OS X (10.7.3)