If it still doesn't come off by turning counter-clockwise as described above, use a rubber gripping jar lid opener to get a better grip on the metal ring. As a last resort, find a big strong male (again), have them wrap black tape around the metal ring, 2-3 times around will do, then use a large channel lock tool to grip and turn the ring and it will come off. The black electrical tape will keep the tool jaws from scratching the metal ring.
The LED replacement bulbs is a great suggestion. Uses less power, stops you from burning yourself every time you touch one, as well as less heating up of your unit on those warm nights!
Days camping (2015)----88 days
Days camping (2016) ---110 days
2016 Wildcat MAXX 28RKX (33' TT), 2007 13' Scamp
2015 Ram Laramie Hemi
30 years RV'ing
12 different RV's