Anybody know how to loosen/remove the aluminum crimp rings that clamp
the tubing to the tee fittings?

I have to replace a section of 1/2" polybutylene water line in my
camper. This is the gray stuff used years ago (camper is 1991 model)
and a piece of it is leaking. I can't seem to stop the leak, so I am
ready to just replace the section of tubing. I don't see a way to
remove those aluminum crimp rings.

Ideas?

TIA

Jerry