Follow Hotrod Lincoln's instructions on prepping the cab for inside work. A sheet of 1/2 inch plywood will be more than enough. Extend it a couple of feet outside the cab supported by a couple of concrete blocks. As Jerry said, try not to fall asleep once you get under there. As soon as you do your buddy will shock you awake and you will have a dent in your forehead that matches the curve of the bottom of the dashboard. Good luck, you got this!
