battery terminal

No, don't cut any factory wires.

You should be able to unbolt the end of the terminal from the rest of the cheap rolled steel battery clamp. On my corolla it has a small threaded stud and the tab from the fuse terminal is held on with a wing nut.

step one, attach the stinger clamp. Actually, keep this disconnected from the batt terminal until you're done. Better yet, remove the battery just to be safe. It's no fun to arc a battery and it can be dangerous. Just do the wiring first, then connect the battery. If you have disconnected the negative side and are careful, it is safe too.   

step two (assuming there is a bolt or second tap) attach a short wire of the same gauge or greater than the lagest of the factory wires (ie the same size as the factory ground) terminate that with a ring terminal, attach the ring and the factory fuse terminal together with a nut and bolt and star washer(s).

Be sure to insulate well with shrink tube or electrical tape and tie up with zip ties, cover this with some wire loom too. If you want it to last forever, solder the crimped terminal, use dielectric grease in your connections.

If you are running 0 from your positive terminal, there should be 0 from your negative too. Check out any posts regarding the 'big three' if you want more details.