It isn’t an emergency. Try to raise the humidity in the viv. Put large water bowl in so the snake can soak if it wants. Put the bowl over the heat. Maybe spill some water. Cover part of the screen to reduce ventilation. The snake will probably finish on his own. Check to see if the eye caps have come off. That is the most important thing.
If it looks like the snake is being constricted by dry skin, I might soak him again. A little dish soap in the water helps. But if the snake doesn’t appear to be having problems, I just wait to see what happens on the next shed.