Can you factory reset a icloud unlocked iphone?

I recently just bought a iphone 6 from this guy on offer up. He showed me that it unlocked and was signed out of icloud and every thing was reset. He just forgot to take the password off and i no longer has his contact informatuon to text him what's the password. So can I reset a icloud unlocked iphone?

As long as it isn't logged into his Apple account, you can enter DFU mode and restore it via iTunes on a computer. DFU mode will allow you to restore it without entering the password however it doesn't work if Find my iPhone is enabled.

You can find out how to enter DFU mode here

Yes