I just installed my Hayward SP1091LX Skimmer and took pics along the way. Hope this will help you guys out, since most of the threads on this are missing the pics!
So just a few things first, I have the bigger 2650 gph pump so my intake and return hoses have been upgraded to the larger ones that came with it, your setup may be different. Here is how I cut in the new hoses and intake and returns.
Also I drained the water down for this installation. (I had high salt levels and needed to backwash my sand filter anyway so it just made sense to drain the pool down for me)
Ok so first I grabbed some teflon tape and wrapped the threads on the smaller piece where the existing intake hose will attach onto when we are done. I wrapped it around each set of threads twice and worked my way down the fitting. Hand tighten all the way in when your done!
Now onto the butterfly gasket. Get a sharp razor blade or x-acto knife. I pushed the gasket apart on a flat cardboard box and cut from the inside out. I did this because when the two sides of the gasket are flattened like this it creates a nice center groove for your blade to cut right in the middle!
Donít rush! I cut from one corner to a little past the middle, the turned it around and finished each side, that way I didnít slip. And voila! two gaskets!
Like I said earlier I drained my pool down to do the install. I chose an area in the center of two uprights and wiped the inside and outside of the area clean.
Next I took the hard plastic square piece that will go on the inside of the pool and a black marker and marked exactly where I wanted the holes. I made sure the top holes were below the grey seam. Then I took a small screwdriver and carefully popped holes where my marks were.
Next I put on one side of the gasket with one screw onto the plastic piece.
I pushed the top two screws in with a phillips screwdriver so the holes would stay tight around the screws.
I put all the screws in with the screwdriver to get the holes enlarged. and test fitted the outer gasket.
Next I backed all of the screws out except the top two outside ones. Since I was by myself I grabbed my little drill to ďstartĒ the top two screws into the skimmer. It was easier than trying to hand twist a screwdriver and hold everything in place at the same time.
Once I got the skimmer to hang in place I checked the gasket on both sides to make sure it was even and lined up. Then start screwing the other screws in by hand. I tightened the center ones on each side and then the edges. Tighten the screws a little at a time, youíll start to feel the screw get a lot harder to tighten.
The gasket should be snug and not lift when you move the skimmer around a little. Check the gaskets all the way around.
Now the moment of truth, your about to remove a huge chunk of your pool liner! Donít worry itís easy, just slowly cut along the inside of the plastic, with out cutting the gasket material.
Next lock your intake shutoff valve and remove the hose, (youíll get a little water spillage, just keep the hose upright), put a hose clamp over the hose end first, then slide the hose onto the bottom of the skimmer and tighten the hose clamp just below the lip on the hose.
Slide the door in place, drop the filter basket inside and put the top round cover on!
Slowly fill your pool back up if you drained it and check for leaks from the gaskets or where the hose attaches.
Now enjoy how great the surface of your water will look!