A method is provided for using a collar to either drive a post into the ground or remove a post from the ground. The method includes, when driving a post into the ground, coupling the collar to the post in a first orientation so that a post opening of a first portion of the collar extends about the post, and applying a driving force to a second portion of the collar. The method also includes, when removing a post from the ground, coupling the collar to the post in a second orientation, rotated approximately 180 degrees from the first orientation, so that the post opening of the first portion of the collar extends about the post, and applying an extracting force to the second portion of the collar.