Turn off the pump and lower the water level in your above-ground pool to at least 2 inches below the current wide-mouth skimmer faceplate. Not only do you need room to work, but if the water level is too high, it seeps between the pool liner and the wall when you remove the old wide-mouth skimmer.
Remove the faceplate of the old wide-mouth skimmer by removing the screws holding it to the pool liner. After removing the faceplate, replace the screws to hold the vinyl liner in place. Doing this keeps the weight of the water from pulling the lining down while you work.
Disconnect the old wide-mouth skimmer from the pool wall by removing the four screws holding it in place.
Align the new wide-mouth opening with the old screw holes. Before attaching the opening to the outer pool wall, insert the rubber seal that comes with the kit between the wall and the wide-mouth skimmer opening.
Fasten the wide-mouth skimmer opening to the pool wall using the screws provided in the skimmer kit.
Affix the replacement faceplate on the inside of the pool. As with the wide-mouth skimmer opening, insert the rubber seal that comes with the kit between the pool liner and the faceplate. Using the screws provided, affix the faceplate to the inside of the pool. The screws will penetrate the face plate go through a pool lining, the pool wall and into the wide-mouth skimmer.
Attach the skimmer basket to the other end of the wide-mouth skimmer opening. The wide-mouth skimmer opening funnels into the actual skimmer and skimmer basket. The skimmer is attached to the outer end of the wide mouth opening by four screws. Before attaching the skimmer basket, make sure to insert the rubber seal in between the back end of the wide-mouth skimmer and the skimmer basket.