How should I treat rust on inside pool walls

[avcahill]

I have a 12 year old above ground pool. Last year the liner(the original), which is a J-hook type, started leaking late in the season. I purchased a new liner in August but never got around to installing it before the cool weather got here. During the winter it failed completely and the pool drained. Upon checking it this spring, I found a couple of small area of surface rust showing through the black coating on the inside walls of the pool. How should I go about treating this rust before installing the new liner? Also, is installing the liner something that can be done easily by my 15-year old son and I, or should I follow my wife's advice and hire a pool professional to do it? My pool has sand under the liner which was sloped up at the walls to form a cove. I have seen the foam padding for the walls under the liner, the foam cove strips for at the base of the wall, and the "shield" material for under the liner. Is this stuff a good investment? Any other installation advice will be greatly appreciated.