Can I garnish wages from unpaid rent & how do I do it? If the renter receives disability can it be garnished as well?

Can I garnish wages from unpaid rent ...
You have a judgment for wages due to you?

And you want to garnish rent owed to a landlord who you have a judgment against? Probably. Apply for a writ of garnishment directed to the tenant, instructing the tenant to pay the rent to the court (which would then pay it to you after judgment debtor's right to object has expired) instead of to the landlord. Specific procedures would depend upon your jurisdiction.