mobe.....I found the best way to install the grips was like i said,,cut the connector off of the end of the wire on the right grip,leaving two or three inches of wire on the connector you just cut off. Add 20 inches or so of new wire, solder and heat shrink the connections, and pull it thru from the right to the left. Use something like liquid soap to lube the wires.
The hard part is finding something to push thru the bars over, under or around those internally wired switches. Help the right grip back on the bars, dont just try and pull it on with the wires you are pulling. One other thing about the wires, one is black, the other is black with a white tracer. Make sure when you add the wires you know which one is which so you can solder them back properly.
Tp pull the wires, I used something called ny-rod. it can be found in most good hobby shops and is used for control surfaces of model aircraft. Its maybe 1/8 inch by 36" and flexible nylon with a hole all the way thru it. You need two pieces of it and you connect them together with a short piece of all thread which they will have also. It will push right thru the bars with no trouble at all. I smoothed the end of the ny-rod with sandpaper so it would not catch on anything.
Once you get the wires thru to the left grip, cut the excess off leaving two inches or so of wire sticking out. Strip those wires, strip the wires on the connector you cut off, solder everything, black to black, black w/ white tracer to black w/ white tracer, remembering to put the heat shrink on BEFORE you solder. (dont ask how I know this one) Then plug your newly soldered connector into the left grip connector. You will not need the extension wire adapter as you have made up that difference with the wire you just added.
Once you are happy everything is tight and protected, push the wires back into the bars slowly and carefully, feeding the left grip on. then just push it the rest of the way on all the way up to that 4 and 3/4 inch mark they tell you to put on the bars in the instructions.
I used the stealth grips and they give you a super easy way to wire everything up, no cutting or splicing of wires. You can always use the switched method, but the way the factory does it, its pretty much foolproof and the grips will not heat unless the bike is running.
I also used the ny-rod to pull the wires under the gas tank. Just take out the rear mounting bolt, the front two bolts and push the ny-rod under the tank to the front of the tank. It helps to have a helper here to run either the ny-rod or lift the tank slightly.
If you need anything else let me know...
Tom