Yes ma'am!Did you try WD 40?
Part B is....WAIT!
Impatient me, I tried right away and I couldn't get it off. Then started to call in backup.
When I tried in the morning it'd had time to do its job and I managed to back the nut off. Granted it took 10 minutes to back off a 1/2" worth of thread but it came off easy enough.
And the icing on the cake: I got some eye candy time with HTG!