Two people - Solders A & B - make this an easy task.
One watched the timing.
Put the Transfer Case in NEUTRAL and the Transmission in 2nd Gear. (or another gear if you want different torque and effort applied).
THEN, Solder B crawls under the truck and, using a pry bar or long pipe wrench on the U-Joint at the back of the transmission, slowly turns the engine over by turning the drivetrain by "armstrong" forces. (It's really not a hard job. Just takes teamwork to have eyes and arms in the two places simultaneously.)
Have fun.