Take care to not let the tailgate fall on you as the lifts are removed. Have a helper hold the tailgate open, or use a secure method to hold it open.
Using a screwdriver (A), lift up slightly the socket clips (B) of both ends on the lifter (D), and then remove the lifter from the bracket (C).
Push the socket of the lifter into the bracket for installation.
Make sure the tail gate locks and opens properly and locks securely.