How do I remove plastic shutoff valves?

[brown...@earthlink.net]

I am installing cabinets where I used to have a free standing
deepsink. The problem I have is with the water shutoff valves. The
flexible risers are permanently attached (no way to remove them from
the valve) and I don't want to cut a huge hole in the back of the
cabinets to get them in. This would normally be straightforward
except for the valves themselves - they are made out of a white
plastic, have a push/pull mechanism to control the flow, and there is
no obvious way to remove them. They are not Sharkbites (near as I can
tell) and they don't screw onto the supply pipe (since there is no
place to attach a wrench on either the valve or the supply pipe). I
can't find a picture of them anywhere on the web and my local hardware
stores have never seen valves like them when shown a picture. I am
hesitant to start pulling on them or twisting them for fear of
rupturing the supply line. Does anyone know how to remove them?
Thanks!

[ironmike]

If things are as you say, I guess your stuck with shutting off the
water supply, cutting the valves off of the water supply pipes, and
then reinstalling standard shut-off valves. You might have to couple
a short piece of pipe on, and then put standard supply valves on. I
assume these valves are glued on to plastic pipes or they're soldered
on to copper pipes?

Either way, just add some pipe and caps so that things stick out of
the wall, then cut nice holes in the new cabinet, then cut the caps
off and put the valves on.