I didn't think about documenting every step on this until after I was almost done. Here are some pics that show the overall process of what I did.
I needed a place to mount 4 switches and I wanted to be able to reach them easily while driving but I also wanted somewhat of a stock look. I ended up with this solution. I used ABS plastic to cover the slot next to the pedal adjuster. I had to take off the entire lower panel to do this. You need a 7mm hex head driver.
Once the panel is off, cut off the backside and top of the cubby hole. This is necessary for wiring your switches.
To make the template for the ABS plastic, I placed cardboard on the ground and put the opening of the cubby hole on top of the cardboard. Trace the shape of the cubby hole and you now have a template that you can transfer to the ABS plastic. I bought a small sheet of the plastic (12"x12") from a place in San Antonio that sells auto and marine upholstery. They charged me $5. Any car audio shop should have some, also.
After you transfer the template to the plastic and cut it out, fit the piece in the hole to make sure it fits. You shouldn't have many gaps but it's ok if there are some b/c they will eventually be covered with Bondo. Use a hot glue gun to glue the perimeter of the plastic from the front and the back to the dash piece. Once it cools and feels secure, lightly sand the glue to remove any globs. Now use Bondo over the top of the ABS plastic. It needs to be sanded pretty smooth because it will get spray painted to match the stock dash piece.
After the Bondo dries, drill whatever size holes your switches need. In my case, they were 5/16" holes.
Now spray paint the new plastic section that you added. I got a color from Wal Mart (Krylon Camouflage in an Ultra Flat finish) that matched my tan interior almost perfectly. I put on several coats. Mount the switches.
For my wiring, I went with slide on connectors rather than soldering them on. This lets me easily swap which switch is connected in which location. I used 18 gauge wire and wired each one to a relay. You can see how I wired them in the first picture. I chose different colors for the top post so that I know which wire is routed to each switch.
From here you just have to put the dash back together. I have done it enough times that it only takes me 2 or 3 minutes to get it all apart/replaced. Hook up your wiring to whatever you're trying to run and you're set. Here are some pics of the finished product. The switches have blue LEDs on them that illuminate when there's a load on them. It puts off a subtle glow in the cab. You can find any color LEDs that you want on the internet...I hear TANK prefers the purple ones.
Finished Product
The most expensive part of this was buying the switches. I spent $25 on the switches, $5 on the plastic, probably $10 on additional wire that I didn't already have and $20 on a case of beer while I waited for the Bondo to dry. I had everything else.
I left out little things like how to take the dash apart and the wiring but I figure ya'll already know this stuff. If not, just PM me with any questions. This was my first little "how to" write up so I'm sure it's not real clear...take it easy on me.