Activation Screen On iPhone4?

So my dad gave me his old iphone 4 he doesn't remember his password for the account and i can't get passed the activate iphone screen. I youtubed almost every video and nothing is working…
someone please help. Links will be useful if you can provide them please and thank you

You could always try a "brute force" method. Since it's a 4 digit code, that means its somewhere between 0000 and 9999. That's 10,000 possibilities, which is not really as many as it sounds like. Start at the bottom and work your way up. 0000, 0001, 0002, etc. OR you could take it to your cell provider and they can probably get it open.

Yes you right john