Originally Posted by
~Rich~
A slingshot is very simple, place a tree trunk protector and snatch block up further than the car ( which of course is first in line and unable to proceed further) around a good anchor point, run the rope up to the snatch block and back behind the first car to one behind. The second car reverses back ( or turn around if able) and with the first car driving pulls it forward. The use of more snatch blocks can reduce the load required to assist. This page might help explain the concept: