Heat the bolts that go into the hub from behind with a torch (propane or Mapp is good enough for heating loctite) in the front where the threads go into the hub, GM uses red loctite on them and heating them makes them easier to remove.
The loctite prevents corrosion so they don't rusted in, heat them one at a time as you remove them. Blue loctite is fine for reassembly.
A hammer will usually knock it loose even in the rust belt but sometimes they are corroded in pretty bad (aluminum knuckle), remove the CV nut, knock the axle in a bit and use a long punch from behind to carefully tap the hub out. Be careful and protect the boot with a piece of cardboard and a couple of zip ties.
The rust belt does bad things to parts that normally drop out in other parts of the country.
Clean the knuckle face and opening with a roloc or drill mounted wire wheel and put a thin coat of never seize on them to prevent the new ones from corroding in there. Axle nut torque to 118 ft.lb This is the latest and last revision of the torque spec, you find specs all over the web with anything from 118 to 178.
When higher torque values are used the hubs tend to fail prematurely.