Does anyone know how to reset firmware password?

Hello there

Few days ago a got an used macbook pro 15" but my surprise was when I turn it on the computer asks me a PIN CODE, and I don´t it, so I tried to restart the IOS and I can´t get it because it also request me a password.

Does anyone know how to fix this? I´ve tried removing RAM memory but it didn´t work for me.

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0