The sink's water valves are leaky and shall be replaced. The are mounted on CPVC pipe that originates in the wall. Fortunately, if the PVC is cut, there will be enough PVC protruding from the wall.
Is there a best practice, such that I can avoid losing pipe every time the valve must be changed out? Fortunately this valve has provided service since 2004, so replacements frequency is approximately 15 years.
UPDATE
The photos shows the front of the valve removed and was replaced with a new part. Seems dry / water tight, while under pressure.