How can you get a phone unlocked?

[Nana8]

My nephew has a Samsung note 4 he is saling he dropped contract if I buy it can it be unlocked

 

[webworkings]

Please read the article in the forum about "passwords, lock codes, etc.," http/www.tomsguide.com/forum/id-2311806/read-passwords-lock-codes-pin-numbers.html