CPL & MC protector threads are stuck

[Raj]

Help.
I usually put a MC protector on my lenses. I did the same on my sigma 24-70. I then put the CPL. I dont remember when but now I cant get the protector & CPL separated. They are both stuck to each other. I can take out both from the lens though, so its not a shostopper.
But i do want to sepaarate them.
Any usualyfull ideas other then using a hammer or plyer ?
Both the protector & CPL are 82mm & quite expensive. I dont want to spoil them. FYI, i didnt dropped them or anything like that. I guess I may have tightened themm too much accidentally

[Jaymz]

I can not remember what they are called, but there are 4x4(very very thin) inch rubber pads used for gripping on to and opening jars, maybe something like that?

[Raj]

I can try it. But i think I am getting good grip, although not too broad. Especially, CPL's static ring is not smooth. I just cant turn the two filters at all.