I would soak him. Place him in lukewarm water ( check temps with a tempgun or outdoor thermometer ) around 80 - 82 degrees and let him soak for a while. Be careful not to put too much water in the container . You only want him to soak, not swim. Too much water could drown your snake if he tires from moving around in whatever you soak him in.
After about an hour the skin should come off very easily on its own or you might let him crawl through your hands with a damp cloth around his body. This should do the trick.
I would wait till he gets that un-shed skin off before feeding him.
Best to you.
Yosef