Just got used game, access key not working?

I just bought Factions from a friend. Unfortunately when i try to add the access key to my original account it claims the access key is in use. Now, this is understandable because the other account is still active. I have his login info and am unable to find a way to deactivate the account, or add it to my original account. Any ideas?

Each Factions CD-key may only be used once to create a new Factions account or upgrade and existing Prophecies account. Once used, that key will no longer be accepted by ANET's account handling system.

If you want to use that access key then you will need to use the account he has allready made.

This will involve changing the email address, password, and if you want deleting all his characters, (if i were you put any gold (money) he has in storage, then delete the characters) if you delete the gold then you will be kicking yourself later on in the game.