How to tell if my T is finished molting?

I have a Chaco golden knee tarantula. His abdomen has almost no hair on it. He is staying is his hut on the warm side with a substarate wall over the entrance. witht eh restr of the opening silked shut with web. and he hasnt eaten in a while. so i took all of his food out and left him alone. But HOW CAN I TELL THAT HE IS FINISHED MOLTING????(: Thanka!