Rob,
Since the top fork nuts (bolts) attach to the damper rods, you will need to remove them from the damper rods after you remove the top fork nuts form the tubes. You will need to remove both top nuts and be prepared for the front of the bike to drop when you remove the second one (or figure out some way to compress the remaining spring enough to get to the locknut on the underside of the fork nut (bolt). Then you will need to lift the front of the bike to re-fasten them.
An easier solution would be to remove the two small nuts on the the studs holding the tachometer from the bottom of the aluminum housing. Then simply lift the tachometer from the housing.