I pressed the bottom and top cup separately, in that order. It didn't take long and the press worked perfectly. Now I'm off to the hardware store to get a small length of pvc to seat the crown race. Not knowing how well the pvc will take the pounding, it may be a one-use tool, but that's OK. It's a 1" steerer, and this is my only frame that uses that size. It will probably be a one-use tool anyway, for that reason. But you don't know what frame/fork might be joining the herd down the road, so maybe not.

Thanks for the replies, that's one task finished up.