Happens every day. Friend gets a loan for the truck (or has cash $$$), he pays your bank directly for at least the full loan amount (can pay everything, the difference will just be refunded to you) and you get a lien release. Then you can sign the title, bring the lien release to the DMV and he can register it.
If you owe more than what he will pay you, get a personal loan (maybe secure it with other collateral like a CD or something) so you can pay off the difference.