Originally Posted by Deftmetal
The nut is off, that means its loose. It is simply stuck. Sorry about all the extra information.
clamps that work like this one does go on easy but don't come loose very easy. Tap on the stud gently to make it go down towards the battery. That will allow clamp to spread more easily
Oh I completely understand you now.
Unscrew the negative and then unscrew the nut on the positive and tap it/ pull it up?