starter problem

ok so i flipped my jimmy back in march and i'm just now getting around to fixing it, i had someone fixing it and when they put the battery in they flipped the wires and melted all the battery cables. I'm in the process of replacing them but the owner before me tried to rig it up all fancy so now i have to ghetto rig all the wires, etc anyway my problwm is this: i can't release the the bolt on the starter from the wire its holding in place, i think in the process of flipping the wires on the battery they grounded out everything and accidentally welded the bolt and the wire together, anyway...any suggestions on how to get it off? i'm trying to see if the starter and alternator even work anymore....

Welcome to AF.
Do not try to rig it replace what is burnt or bad.
Fix all shorted and burnt stuff first.
Are you asking about the big bolt and nut on the starter solenoid?
If so will the nut screw off?