reset a pre-owned apple TV (3rd gen)

A friend of mine gave his apple TV but forgot to reset it. Now, I've been trying to reset it using the remote, itunes (itunes cannot detect the device) but it seems it doesnt work.

I have only 2 options when the TV boots up, computers and settings but i cannot control those. The original owner tried to remove the device from itunes and its not listed. How do i reset this then? any suggestions?