You are talking about a bearded dragon?
Any vegetable oil will work OK. Just apply a little, wait 20 minutes and gently try to remove the skin.
Even if things are dry- shouldn't normally be a problem for him to shed. The older they get, the less often they shed and the longer it takes.
I did have a shed problem with many hatchlings once when I tried using tetra's supplement (can't remember the exact product any longer, may have been calcium with d3 and phosphorous or a multivitamin). It had horrible effects on shedding- made the dead skin very hard and they could not easily remove it. If by any chance you are using a tetra brand supplement, stop using it.