How do I go about changing rehab facilities for my husband?

Have you already talked to the new place? When we switched grandpa, the new facility helped my mom get him transferred over. We called around and found a facility that had rehab beds available and discussed his situation with the admissions person. The admissions office at the new place actually contacted the first facility and let them know he'd be coming over. I don't know if that's how it works at every facility but it's how it happened at ours. You might have to pay for transportation.