Don't know if you got it off yet, but I had to weld nuts on to mine, then use a gear puller, but if you plan on re-using your rims, not a good idea. In another instance, I had the tranny sitting on concrete block with a 2x4 under the tires. Unbolt the top of the case, extract each axle, then us a rubber Get a dremel and polish the axles up once the tire's off. Unless you go with a new straight axle.
On a side note, chalk your tires. If they move once that case is off, and if you aren't paying attention, then it shifts all those gears all around. Learned the hard way on that one.