How do you get wrinkles out of a above ground pool?

This is a really hard thing to do, especially if it is full of water. The best way is to monitor it as it is filling and pull/tighten the liner as it fills up. Keep the edges tight but not secure and let the weight of the water pull it down into the contours. You should always keep the edge retainer a bit loose as it is filling so the liner does not stretch out. I am guessing you want to know how to do it when it is full. I have done it but it took quite a while, most of it spent underwater. What I did was to go under and move the wrinkle inch by inch toward the nearest edge by pulling it in the desired direction taking into account for the direction of the wrinkle. The wrinkle may travel in a sideways direction depending on how the slack was gained. Once you get it to the side, work it up the edge to the top, then undo the top clamp and pull the extra over and reapply the clamp. Sometimes while trying to remove one wrinkle you will make another, it is because the bottom is uneven and the liner has quite a bit of weight on it.
This is a really hard thing to do, especially if it is full of water. The best way is to monitor it as it is filling and pull/tighten the liner as it fills up. Keep the edges tight but not secure and let the weight of the water pull it down into the contours. You should always keep the edge retainer a bit loose as it is filling so the liner does not stretch out. I am guessing you want to know how to do it when it is full. I have done it but it took quite a while, most of it spent underwater. What I did was to go under and move the wrinkle inch by inch toward the nearest edge by pulling it in the desired direction taking into account for the direction of the wrinkle. The wrinkle may travel in a sideways direction depending on how the slack was gained. Once you get it to the side, work it up the edge to the top, then undo the top clamp and pull the extra over and reapply the clamp. Sometimes while trying to remove one wrinkle you will make another, it is because the bottom is uneven and the liner has quite a bit of weight on it.