Replace Grohe 3/4" Thermostatic Service Stops

I need to replace the service stops in 2 3/4" Grohe thermostatic valves installed in 1996. Does anyone know if this can be done and, if so, where to get the parts? I also need to replace the service stops in 3 Tempress II pressure balance valves. There are leaks in the copper lines, and we have to push epoxy through the valves to take care of the leaks. Thank you.

grohe

YOu get them from a dealer who handles Grohe faucets. Why isn't the epoxy coating company dealing with the stuff you need?