I fixed the leaking return fitting this weekend, using a styrofoam cooler and it worked better than expected. What I did was take an old small styrofoam cooler, put weather stripping around the top and then cut a hole, large enough for my hand to be able to reach in to hold the fitting. I had my wife hold it over the fitting while I remover it from the pool wall. As soon as the water ran out that was trapped inside the cooler, the thing suctioned itself to the wall creating a dam that was completely water proof. I change the fitting and then removed the cooler, which by the way was pretty tough to do, we had to fill the cooler about half full of water before I could get the thing off the side of the pool. Anyway, just thought I would share my experience, so if you have to do this it is a fairly inexpensive tool that will save you from draining your pool down.

By the way, the bucket idea would have worked as well, but I didn't have one that was big enough to get above the surface of the water, so I had to use the alternative method.