|Rear Drive Oil Change Tip
Changing the oil in the rear drive for a Guzzi can be a little messy. Try this: get a cheap plastic dustpan (a small one), drill a hole in the handle and attach a piece of wire to it. You can slip the handle in between the spokes of the rear wheel and wrap the wire around the pinch bolt for the axle. Position the dustpan over the container you're going to drain the oil into, open the fill plug and drain plug, and you shouldn't get any oil on the tire or wheel. Cheap, easy and effective.
[Ed. - Todd has used aluminum foil in the same fashion. Perhaps an easier, cheaper way yet.]
See a picture of it here.