Besides lifting the front end of a damaged truck. The front end of a non air shift, sprag transfer case truck needs to be either lifter or have the front hubs removed. I have flat towed my sprag equiped Gasser M35 by spending about 5 minutes with a 3/4" socket pulling the hubs.
A regular air shift truck with no damage can be flat towed by pretty much just putting everything in neutral, using pins that have clips like tractor hook ups and not pins like bailing wire to hold the tow bar feet to the mounts above the bumper. Then, just make sure the front tires of the towed truck have at least 40-50 psi of air in them and drive careful. The hardest part is getting the tow bar assembled and attached because it is so heavy. I use a 2x6 cut to just the correct length that will allow me to back up to an assembled and hooked up tow bar. Then I just need to kick the board out, close the pintle top, run lights and chains before I drive away.
My 12 year old did this in about 10 minutes from start to finish Tuesday before dragging a truck 130 miles behind my Whistler. Read the -10 for the truck and the recovery manuals, under stand them and drive like you have a cargo of priceless eggs at all time.