OSO, I have photos somewhere of a stock rotor in 3 pieces at a local non-Pantera repair shop where they pressed it the easy way. Those rotors are pretty brittle so putting simple press stand-offs under the brake surfaces of a rotor is chancy. Sometimes it works, but sometimes it doe$n't & you'll need a new rotor.
My 'fixture' is a heavy 6" ID cast-iron sewer pipe-cap I found in a scrapyard, with a hole bored thru it slightly larger than an axle flange. I blew a hole in it with a cutting torch, then cleaned it up on a lathe. The hole edge is bevelled a little and catches the rotor right on its sloping flange-edge. Another friend uses a similar fixture made from two pieces of 3" thick plastic blocks glued together. Likely, even a hardwood block would work.
By pressing the 5 lug studs loose (one at a time) first, press- pressure needed to move the axle is significantly lowered. Hitting the studs with a hammer to pop them loose is an un-good alternative 'cause it's really hard to hit the hardened studs perfectly vertically. Any significant side-loads from the hammer will bend and/or crack an occasional $16 (each) stud. Do not ask how I found this out...
Finally, press pressure usually does not exceed 10 tons but even this is sometimes enough to bend the steel front bearing retainer. Before reassembling, check this steel metal piece for flatness and pound it back flat as req'd. Otherwise, the stub axle will be fitted a little further outboard than normal, maybe causing alignment & other problems.
Incidently, I used to weld-repair & remachine stock axles, but the cost of hard-face welding rod went up while the quality & strength of replacements improved and their price dropped, so I no longer recommend repairing stockers. Hard track use WILL crack OEM stub axles right at the chamfer. To do this work, you will need a 1"-2" micrometer that can read to the 4th decimal, as the ideal size will be 1.5876" +0.0004" - zero, and yes- the last digit IS important. Regular mic's aren't good enough.