Undo the cap nuts that hold the unit to the handle bar mounts. Remove the backing plate to the tach, should be 2 small allens, and unplug the tach wires. Tape the connector up and tuck it out of the way using a zip tie. You can put the castle nuts back on the studs, or remove the studs from the cover and use some plastic hole plugs from Lowes or Home Depot. If you go the route of removing the mounting studs your going to have to remove the headlight to get at the trim attachment nuts to remove the handlebar mounting clamp cover. Just take your time. Remember, when frustrated, walk away and come back to it later.
PH