What I do is soak them in warm water in a closed container over their hot spot for about 45 min. If the eyecap does not come off in the water, I put a piece of tape over the cap and then pull it off.
Hope this helps.
I heard that you can actually pull the snakes eye out. I wouldn't recomend doing that!
1.0 BP VPI Pastel - Dante
0.1 BP Spider- Name Unknown (not shipped yet)
Hopefully another one soon!