Jim,
I just completed removing my low beam guard from my headlight about ten minutes ago… Mine is a Bosch unit, not sure if any others were used.
Remove the headlight from the housing. After the headlight has been removed, there are 8 clips that retain the headlight to the rim, 4 on each side of the phillips head screw retainer, they look like a bunch of wires. Press down on the straight side of the last clip and swing it from under the lip on the rim. Do the same for the remaining clips. The headlight can now be removed from the rim, top first. There is a rubber gasket between the reflector and the glass front. Mine was merely pressed in place and came apart using a screwdriver and gentle prying action.
Assembly is in the reverse order. As was mentioned above, keep the inside of the reflector clean and fingerprint free. Haven't had time to check out the resulting beam, so not sure how it is at night, I was never impressed right from the beginning so anything would be an improvement.
Hope this helps.
Doug