Bought a used vita that wasn't deactivated from previous owner's ps3

How do I deactivate it so i can link it with my ps3? Is there a way to return it to factory settings?

Under Settings, select Restore The PS Vita System - believe that'll do it.

You may have to get a new memory card? I have a 16gig one, so I haven't had the need for another yet, but I believe each memory card is tied in with a user profile. Unless there is a way to wipe the card out? Sorry, this may be totally wrong, or totally right.