Whatever you do, do NOT pick at the shed or the eyes.
A warm soak is a good suggestion. It doesnt need to be a long time either. usually 20 to 40 minutes at most. Very little water in a small storage tub. A couple small holes for air. Just dont leave the snake in there after the water cools down which will happen fast if it is not sitting on a warm surface. Also supervise the soak. BPs have drowned in very little water.
After the soak a wet washcloth gently rubbed over the stuck shed may work. If not dont worry. Just keep the temps and humidity correct in his tank. The moment he begins to shows signs of going into shed again begin putting a small dab of plain clear bacitracin on the stuck eye cap once a day. You can also use regular plain neosporin. The one with no added painkillers.
When he sheds again all 3 eyecaps will come off. The stuck one and the one under it including the other eye.