Mazda Transmission problem

I have a 1997 Mazda Protege with the Over drive light flashing and a P 760 code (Shift Solenoid 'C'). I took the oil pan off and measured the solenoid resistances. The green solenoid is 19 ohms, the white solenoid is 19 ohms and the brown solenoid is 4 ohms. Have I found the problem and if so, How do I remove the valve body to replace the solenoid. If you have any other thoughts please reply. Thanks in advance, Steve