Put it on Craigslist. You'll get scammers and tier kickers contacting you, but if you're asking a reasonable price, you'll surely get a ready, willing buyer with cash in hand. In fact, you might want to sell the motor while it's still on your boat so the buyer can see you test run it. Will also allow you to have more $$ in hand for your new motor.
"Decency is not news; it is buried in the obituaries --but it is a force stronger than crime" ~ Robert A. Heinlein, 1952
I can't give legal advice yet, but this site may have some of the answers you need: https://texaslawhelp.org/