Drain the pond water, and remove any fish or plants before you clean and line the pond.
Soak the rag in water, and begin scrubbing the pond after all of its elements have been removed. Algae is one of the most common inhabitants of ponds, and it should slide right off the walls or floor of the pond when you scrub it.
Pour in some dry salt. This will help assist in the breakup of any algae you were unable to remove with the rag.
Use the hair dryer, or any other heated source, to dry out the pond completely.
Apply a coat of contact cement around the inside of the pond and then a coat on the back of the PVC liner.
Heat the cement on the liner so that it welds more easily with the cement on the pond walls and floor. Do not overheat to the point where you cannot hold the PVC in your hands.
Apply the liner to the pond, rubbing around it to make sure it is glued on tightly. Applying more pressure will help ensure that no air bubbles are present between the liner and the pond walls.