Heres a link for the SAS I just did on my truck.
My truck was also2wd when it left the factory, but somebody already converted it to a TTB setup with 4wd coil buckets. But this build would be extremely similar to what you would have to do. The only major difference is that you would need to swap out your transmission to a 4wd style and add the transfer case. You would also need 4wd drive shafts (stock 4wd ranger rear, Jeep Cherokee front, if you use a Ranger transfer case and move the front axle forward like I did). But like everybody said, you need to do a lot of research and think about what you really want before you take on a task like that.