Believe it or not, a pair of side cutters. Wire cutters, Dikes, whatever you want to call them. Use the cutters to get inbetween spring coils near end of the cable. Compress the spring, then gently grab ahold of the cable. The cutter blades will dig into the cable and help you hold the spring, but won't generate enough force to cut that big cable, IF you're gentle. It's always worked for me.
Good Luck!
