For starts I had a real hard time getting them out, they were all rusted tight so I ended up having to beat them out. I got the HD greaseable ones from Paragon for replacements. One trick I discovered is to clean up the inside of the flanges real well and then lube them up with a little grease before pressing the cups in, it makes pressing them real smooth. 

It's super easy to bend the flanges and I had a lot of trouble getting the snap rings to seat in the groove and still have good play on the ujoint. I still don't know if it was me screwing up or the new u-joints.

I broke a c-clamp(made in china) trying to get them out and I bent a flange with the ball joint press  putting them back in. That's why I say take em to a shop cause at least they might be able to fix a bent flange rather than buying a new one. All in all good luck! I hope it goes easier for you than it did me.