Just to expand a bit, the axle retaining nuts will be inside where the handbrake shoes are. You can get to them by rotating the axle so that the largest hole in the wheel flange (the bit where the wheel studs are) lines up with each nut, then undo them with a socket and extension bar through the hole. Once undone, as above, use the rotor as a slide hammer, put the rotor back on but backwards, so the handbrake drum is facing out. Fit two nuts on backwards (so the taper faces out) about 5 or 6 turns and then grab the rotor, push it all the way in, then pull it out firmly, this should break the seal and the axle should pop out.
If you jack that side up so the end of the diff is higher than the centre, then you won't lose any diff oil.