I had a tenant sue me in small claims for his deposit. I had given him close to half of it. The court ruled to make it exactly half plus court costs. I paid him via certified mail the very next day. Months later, it's popping up on my credit report because he requested an abstract. My questions are: first, how can I get a release on the judgement if he's unwilling to sign? Second, can he put a lien against that property?

He could try a lien but I would not hold since you have prof of payment.

You contest the credit report and send them proof of full payment

The issue, you did not go though an attorney or escrow agent who would have held the money till they had the signed release and then would have released the money

He could try a lien but i would not hold since you have prof of payment. ...

In most places that I know of, simply recording the judgment constitutes a lien. He has probably already done that. The only mechanism available to remove such a judgment lien would be to sue the judgment creditor to remove the cloud on title, and for damages for refusing to give you a satisfaction (release) of judgment.