Be real careful with the tail. Try setting him on the bottom of a tub with a wet paper towel over the whole body except the head (if you try just doing that with the tail he'll just crawl out). Let it go for 5 or 10 minutes and try working it off that way. I had a neo with a nearly complete shed stuck earlier this year and got it off this way in about twenty minutes.
Cool snake though... you don't usually see the white spot on the head like that. Ours always start changing there first but it always goes darker!