I watched the installers of my above ground pool use this method. Subesquently, I had to replace the liner myself. I used the same technique, and it works wonderful.
You put the liner in the pool as normal. When you have the liner as close to the final position as possible, you put the intake side of your vaccuum cleaner hose down through the square opening for the skimmer. Push it down a ways so that it has a couple of feet of hose inside pool between the liner and the inner wall.
At this point, we had the plastic runners already on the tops of the pool walls to keep the liner from slipping down and in. Turning on the vaccuum, sucks the air from between the liner and the wall, pressing the liner nicely against the pool wall. I also think we used some masking tape to seal the edges of the liner against the part of the skimmer opening (from the outside) the idea being to keep outside air from being sucked into the liner space.
As the liner pressed and conformed itself to the ground and the walls, we began to fill the pool. As the pool filled, the water pressure combined with the suction, made a wonderful installation.
Of course you cant fill the pool all the way, as your skimmer isnt in yet, but I bet you could install the skimmer first, and slip the hose down a different area along the wall, and fill it even higher.
I just did as I saw it being done. Works very well.