A friend of mine decided to encrypt his Private Key with a BIP38 protocol. And now he does not remember the Password. 18BTCs is the Amount of Bitcoins in that Wallet that is encrypted.

Any idea to decrypt that private key?

My friend is willing to give a fairly generous reward to anyone who can help him recover those Bitcoins.
My friend has, his private key encrypted, but he does not remember his passphrase.

Regards!