I've never used a press for driveshaft u-joints, always a hammer. If the stock joints are still in there, use a torch to melt the plastic out of them, then beat them out with a hammer.
For axle u-joints I've never had to do it without a press but I think it'd be a nightmare.
Tim
'84 Chevy K10, lifted, loud, fast, and 3/4 ton axles