Hi! I'm new here and I think I already like this place

I own a Geo Tracker, a Chevy Sprint and even a Quad Runner 185 ATV :P Really like zukis!
So, I bought my Geo Tracker 1997 4x4 manual this summer. Everything is up and running well except for some eeps! here and there but nothing serious.
The first I'd like to fix is the clutch system. I'm almost sure the cable needs adjustment because even when the pedal is depressed, I hear the gears spinning as if it was in neutral and then it's a real pain to get into first gear.
So I went under it with a carpet and my trusty tools and tried to tighten the adjusting nut near the trans and... oops, it's stuck into rust and the whole cable turns along... I could have tried to hook a pair of locking plyers on the stud but I don't want to damage its threads!
Now before I strip another rusted nut on one of my vehicles, I'd like your tips and tricks on this very situation because I'd like this 5 minutes fix not to turn into a 4 houres nightmare (again).
Thank you!!!
Jerome