Always use a new 10 hole gasket behind liner & behind light retaining ring. The liner is also a gasket, but you will need new gaskets, the old ones will already be pressed down.
Take light apart and inspect all parts for corrosion. Replace all screws deemed unusable, including the retaining screw, they are all Marine Grade Stainless Steel. Your local pool store will order or have screws in stock, they are machine screws plus speciality items but the big box stores may have something comparable.
Two ways to install Stainless Steel\Plastic retaining ring:
1. Install retaining ring screws before the liner goes in. DO NOT OVER TIGHTEN, they can break through the copper or plastic back securing ring behind wall. Use spray adhesive or small strips of duct tape to install new gasket. Clean out inside of niche, I have seen some goop that resembles a bad cold, clean it all out, throw towels away & dry inside of niche. If using duct tape, make sure strips go from inside niche to outside of gasket. Don’t put duct tape on pool wall, can interfere with sealing. Picture is showing screws already installed. Find screw head with fingertips, using a #3 Phillips head driver, back screw out, it will make a hole in liner. After removing all the screws, place retaining ring in place then start re-installing screws, top to bottom, left to right. After all screws are in place tighten down tight.
2. Wait until liner is installed to find holes for screws. Using a fingertip, find top two holes at 11pm and 1pm. There is not a screw hole at 12pm or 6pm (10 hole gasket). Using a small phillips head screwdriver poke a small hole in liner then place a screw in hole, hand tighten with the ring in proper place. It’s OK to have the bottom of the light in the water, the electric is off and you will not loose that much water. But you need to work quickly if light is under water. Put screws in bottom 4 holes first, then do the top two. If ring is not lined up with holes, loosen screws and it will line up.

Imperial Pools of St. Louis is presenting this picture installation of an in ground pool light as an instruction basis only. It is highly advised you call an in ground pool liner professional to install your liner and light. WE are not responsible for any problems you accrue while trying to install light or liner. The liability is on the pool owner when attempting to do any project on your own. Remember we are only a phone\email call away if you have a question about installing light or liner.

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