I ran to the same problem !
Hi , Pull up on ramps put emergancy brake on . place in netural . turn switch to low 4x4 . have wife hold brake pedal down hard . crawl under truck an take a 8 mm socket with short extension . slightly loosen the only 8mm screws on the drivers side of the trans. switch . gently & slowly rotate the switch till the low 4x4 enguages then tighten the switch . don't over tighten the plastic switch !! I turned my switch farward to make adjustment. Bud