Erm give him a bath then let him slither through a damp towel, u cud try gently running ur fingers over the skin to see if it will peel off easy before hand though!
warm bath (use a thermometer to check temps), damp towel, damp moss hide, water bowl over heat mat to raise humidity in viv, fingers (as said above, but dont force it off as you could remove scales)
good luck!
9.11 Cornsnakes 1.1 Hogg island boas 1.0 Dwarf Burmese python