Marking problem as unsolved

[tiredtyrant]

Hello. A friend of mine solved a problem and submitted it under my account. Since it wasn't the one to solve the question, I'd like to 'unsolve' it, is this possible?

[hk]

If you PM me the problem number I can do it for you.
Please enclose the email address you use on PE in the PM as a check that I pick the right account.