A collar is provided that can be used to either drive posts into the ground or remove posts from the ground. The collar includes a first portion defining a post opening adapted for coupling about a post, and a second portion coupled to the first portion. The second portion includes a receiver adapted for receiving a tool for use in driving the post into the ground when the first portion is coupled about the post. The first portion defines an obtuse angle with respect to the second portion. The collar is configured to be positioned in a first orientation about a post when used to drive the post into the ground, and a second orientation, rotated approximately 180 degrees relative to the first orientation, when used to remove a post from the ground.