Provent-A-Mite. Look it up online. Quarantine him from your other reptiles and give him a good long soak-- while he's soaking, treat everything in his tank (both sides since you made it smaller for him, wouldn't want any to get anywhere else in the tank and hide) with the Provent as the directions tell you to. It's the best stuff out there.
DO NOT TREAT HIM DIRECTLY WITH THE P-A-M THOUGH. Just let the living ones on him drown in a soak, and then the Provent-A-Mite will do the rest for any eggs still on him, once you get him back into his sterile container.