How to remove the find my iphone lock from previous owner?

I bought a iphone from a friend and i can't activate the phone without the original owner's apple id.

Take the phone cord plug into computer and also into phone go into itunes and find the iphone and click reset this will wipe the phone from everything. If you don't want to do that you need to go into setting then under itunes or app store then log that previous person out but I recommend not doing that it would be better to just do a reset.

If you bought it from your friend, shouldn't your friend be the previous owner and can't he help you with the ID? (Or was this phone "borrowed" without its owner's permission; i.e. Stolen?) The "Find My iPhone" lock is there for a reason. If the phone is legally yours and you can't find the previous owner, just take it to an Apple store with proof of ownership to get it unlocked. If it was easy to unlock, the lock wouldn't mean much. Oh, I almost forgot… If that phone has been reported to Apple, the second it's connected to a computer that's connected to the internet, the phone will send out a message to Apple with its GPS location.

No matter what the status of the iPhone is, the previous owner is the only person who can remove the phone from his or her iCloud account and free it up for a new owner.
http://support.apple.com/.../kb/ts4515