The best method I've thought of is to pull the lens cap partially off at the bottom. Then squeeze the sides of the light shell deforming it into sorta of an oval which yields more space at the top and bottom. Then there's more room to slip the barb outta the mating notch. The only problem is that the light shell does not squeeze easily. The good news is that replacement lens are available for $7. Lens caps with the single screw on the bottom are generic on many Honda cruisers after '98 ('00+ with Valks). Breaking the light shell at the pesky 'barb' is a generic problem.
*The bottom of the lens cap poses its own problem. The integral tang at the bottom of the lens cap for the attachment screw .... if you tighten down the screw too much the plastic tang will break.
