I had to assist my male the other day. While he was soaking in the bath tub, I got an eye cap off.

I just had a wash cloth that I made him slide his head through. While I VERY gently applied pressure. Came off after a few minutes.

You could also put him in a wet pillowcase. Then in a tupperware thing with some water in it. Put it over the hot side and leave him be for an hour or so.