How do I replace the heater control valve on a 1987 Porsche 944 turbo? on 1990 Porsche 944

Please include detailed instructions about what other parts may have to be removed to access the heater control valve and how to keep coolant from spilling. Include video and/or photo links if possible. I know you just use a screwdriver to disconnect, but getting at it and preventing coolant leak could be tricky.

Asked by for the 1990 Porsche 944
To replace mine I just took the dash off and it was right behind it. Very easy fix