If you got the lockring off of the adjusting cup, clamp a vice grips on the now exposed threads where the lockring used to be. Once you get the adjusting cup, spindle, and bearings out, you should be able to get at both sides of the fixed cup.

Sheldon Brown came up with a method for removing fixed cups using a high grade bolt and nut with a few lock washers. I can't find his page about this method right now, but maybe someone else remembers where to find it.

The basic theory was that you find a bolt as big as possible that still fits through the hole in the fixed cup and put some lock washers on it. Torquing down on the nut from the proper side of the cup can either tighten or loosen the cup in the shell just by applying an extreme clamping force against it. This is apparently the same way that a certain very expensive variety of cup remover works.