Restore and update ipad removes account?

I have searched all over and couldnt find a solution for my question. I purchased an ipad from a friend that moved away, ipad 2 running ios6 currently. I tried to reset the device but its asking for a 4 digit passcode to reset it. I dont know the code and I cant get in contact with my friend until next week. I also did notice his account is still attached to it also, only way I know how to remove it, is to reset the ipad.

My question is, if I put the ipad into restore mode and restore and update to ios 7, will this reset the ipad and remove his account and code from it?