OK here is what you need to do. First gather your supplies. Go to your local auto parts store. In my case Advance Auto is closest. You will need to get some 10 gauge wire. The spool usually comes in 10 or 15 feet, I think.

You will also need a pack of at least 5 ring terminals (the little round wire ends that a bolt can go through).

You will need something to seal the connections. Heat shrink tubing is preferred but electrical tape will do.

Also solder and a soldering iron will be needed to make sure the connections are of highest quality.

OK
Starting at the negative terminal on the battery use a ring terminal to attatch the wire to the bolt on the negative cable.
Pull the cable out about 5 feet or so and cut. Lay it across the engine towards the passenger side. Leave it there for now.
Looking down at your motor from in front of the car, on the front of the right side head you will see a bolt. You are going to look up at the wire you have running across the car now. Cut a piece of wire long enough to eye to that bolt, and run up to the main wire.
Strip back about an inch of the covering on the main wire and solder the line from the head to the main wire. Finish by heat shrinking or wrapping with electrical tape. Do the same thing again on the bolt on the back of the alternator, and again on the passenger side head. There is an open, threaded bolt hole in the front where a 10mm bolt goes right in.

Basically you want both heads, and the alternator ground wires attatched to the main wire. For a clean install, for the passenger side head, cut the main line short enough and put an eyelet on it and use it to ground the head.

I had a grounding mod before this, it did NOTHING. I thought long and hard about it, came up with this, installed it and guess what, it WORKED. The car ran noticeably smoother.

I ran nothing to the body. If you look right next to the neg terminal, there is alreasy an 8 gauge line running right from the battery to the chassis about 6 inches away.
You basically run the line from teh neg terminal to the passenger head front.
You branch lines off of it to the back of the alternator and to the drivers side head.

I DID forget running another off the main line to the standard bolt we all use on the intake. Once will do, just the drivers side.

Your goal here is getting better grounds for the coilpacks, the important sensors, (manifold) and the main electrical system (back of alternator)
The body is already grounded from the battery with a VERY short 8 gauge line right at the battery. You arent going to make a better ground than that. You may want to unbolt it from the fender and clean any paint out from under it to make better contact though.