You're going to need at minimum 2 people... 3 is better.
Is it a beaded liner, j-hook or overlap? The latter will require top rails and stabilizer bars coming off the pool.
Bolding is emphasis
Do not perform this task on a day with winds over 3-5mph!!!! Wind will destroy your pool!!! Ask me how I know!!!
Place the liner in the pool. Position the wall seam away from the skimmer and return. Preferably on the other side of the pool. Once you place the seam, 1 person will stand there and stay there. If its j-hook/overlap, add the stabilizer bars as you go and replace the top plates to the posts as you go. Go around the whole pool. The bottom seam that goes the whole way around the cove should be relatively close to the cove. You need to be in your bare feet or wear pieces of cardboard taped around your shoes.
Once the liner and stabilizer bars are on, someone will get the shop vac and put the hose through the skimmer hole about 3/4th the way down from the outside of the pool and tape it off with duct tape and tape the return hole shut. You're creating a vacuum. Turn that vac on, throw the hose in to fill and leave it on. (You should have removed the skimmer box and return fitting when you removed the old liner.)
Get in the pool. The 3 of you are going to be an equal distance apart from each other and you're going to go around the pool together with your backs to the walls and out reach your hands out to hold onto the walls and start kicking the liner up against the wall with your heels. (Its going to be slippery) That is going to set the liner and pull the air out and you'll see the liner start to lay flat. Its truly a beautiful thing to see. Takes about 15 minutes.
Once you're happy with the set and the bottom seam is even with cove, you're not pulling too much liner on one side, you can start putting the top rails on. To not tighten them down right away. Just enough to tack them down. Make sure your post are plumb and when the last top rail is on, then you can tighten them and add the top caps.
You're done for now.
Only fill the pool on the first day during the day. Turn the water off at night. Start the liner installation early so you can get the most water in the pool one day.
Make sure the weather is above 70° and very sunny. This will help stretch your liner into place!
Again... virtually no wind!!!
Once you get a foot of water into the pool, you can shut the vac off and remove it and shut the water off for the first night. You should be able to do this at the end of day 1 with good water pressure. Use 2 hoses if you can.
The reason you do not want to fill on the first night is because the pool walls can and will collapse. Your liner can pull off. The weight of the water on a cold liner is extreme. You need the sun to stretch it.
If you have anymore questions, don't hesitate to ask. But this should get you through.
