How to Unscrew a Nylock Nut

Just stand in front of the mirror when you exercise, then you won't notice.

Seriously, how did you screw them in in the first place? Just reverse that process.

Yes, you can use them again. Their locking capacity may be slightly diminished, but you'll never know it.

I'd think they can still be re-used without any problems, but if you really want to, they may be thermo plastic, so you could screw them on, and melt the plastic, or you could use a little locknut solution.