You do it by yourself or someone is helping??
I think done the hair ring check by two people is better than only one people.
That's one holding the chin and the other one do the checking.
The main point Courtney had already mention, just one more advice is when the penis slowly shift back into the sheath, make sure the surrounding fur should not have rolled in together with the penis.
P.S. Hair ring checking is essential for a male chin, especially when the chin have a female cagemate. Don't be affraid of such checking, practice make perfect!!
I had another person helping.
I have no problem getting it back in, and I made sure to be careful with the surrounding hair. I just had trouble getting it out, I'm not sure if I wasn't doing it right or what. >_< And I can never really find any specific instructions, most have often been very vague.