Too Tight?!?!?! Kill me...

[E-Revonut]

Do you own a pair of vice grips? A small butane torch? Clamp vice grips on and apply heat to the nut while pulling on the vice grips. If that doesn't work try heating the nut up just enough to melt some of the nylon, when it hardens again it should form to the threads and you could twist it off. Another option is a drop of thin CA or green loctite. It should seep in and bond to the nylon, the bond with the nylon will be stronger than the bond to the steel and after it cures you should be able to get it off. Hope this helps!