I recently bought a macbook pro (2007 model) through ebay. The computer arrived today, I signed in with the account info the seller gave me only to find out it's not an admin account. I can't boot into single user mode, because firmware lock is on, and I can't access any of the apps that aren't apple-made (safari, ichat, etc.). What do I do? I tried emailing the guy but he closed his email account, rather conveniently.