Rear wheel hub removal

I have a failed traction control/ABS sensor on an '04 Impala (70K miles so it is out of warranty). Because of the "integrated design" I have to replace the entire hub assembly rather than just change the sensor. Unfortunately, after complete disassembly of the brake caliper, parking brake piston, and hub flange bolts the hub assembly will not separate from the suspension knuckle. The two pieces seem to be fused together! After liberal application of penetrating oil, I used a small bottle-type torch to heat the knuckle and a small (3 lb) sledge to spank the hub without success. Since this assembly does not have a spindle, a wheel puller can't be used and there isn't enough room get leverage to use a pry bar. Am I going to have to take the entire suspension apart? Even if I do, I'm at a loss at how to separate these two pieces.

I talked to the junk yard where I got a replacement hub and they used an oxyacetylene torch and a 10 lb sledge to get that one off. I don't want to do that to my 1 year old car. Can you help?