Use the "red straw" and get around those studs, the disc pilot flange, then hit the backside of the drive flange at the OD with some penetrant too. Let it sit for 10-15 min, then use a 2# hammer and a good blunt punch to rap on the area around the studs and the disc pilot flange near the center. Keep doing this and before long, something should loosen up.
Are the pads out yet? You might try grabbing the disc at the OD on opposite sides and rocking it by hand. Make sure that the caliper floats freely in & out on the guide pins.