I just had a similar shed problem with my BP's and it was suggested to put the snake in a wet pillow case or snake bag inside the enclosure for two hours. This worked great. A few remaining but, loose pieces came off with some gentle rubbing using a dry towel.
Two snakes were going through a bad shed at the same time. The second snake had retained eyecaps. Another two hours in the wet snake bag and he was all set. I had stressed about the bad sheds and in the end a couple of hours fixed the problem.
I just pulled out an unused humidify and will run that during the daytime and for the shed duration starting when I see them go into blue again. The daily misting didn't work for me. Neither did the moist hides because they would dry out in a few hours.