I was asked to post my procedure for removing the tach from my Mondial. Around the tach there is a black, square, plastic frame. To remove, I used a scraper made of plastic so as not to damage the frame. It is just held in place by 4 plastic knobs which are a press fit into 4 corresponding holes. Just gently pry against the side of the frame and it should pop out. This exposes 4 self tapping screws . one at each corner of the tach. Remove these and the tach comes out. Before removing any wires, I recommend writing the color of the wire at each connection on the white plastic of the tach. The charge from Palo Alto was $159.00 and they turned the tach around in one day. An added benefit I received (besides an accurate tach) was that my odometer and trip odometer are now working perfectly. Previously, the trip odometer would get stuck and would stop the odometer. Spinning the trip odometer knob would get them both going again. Who would have thought that the odometers worked off the tach ? Tom