Need custody advice please. Thx in advance. ?

My nephew has cerebral palsy and he has always lived with my Mom with my sisters permission. Now his Dad wants to take him for 3 hours a week without getting the proper training first from doctors/physical therapists etc. The court told him he had to, he appealed it and they told him he doesn't have to. He is also a known drug head in our town and there was proof until he had his record expunged right before the custody hearing started. What is the next step to try and keep my nephew from having to go there? I'm just looking for opinions.