i made my own slugwrench with a piece of 1/2" a.r. plate and a torch. it works awesome!!! and when in doubt, a cold chisel and hammer will also take that nut off, but will ruin it altogether. or you can heat the nut with a torch, but you risk heating the bearings and destroying the axle seals.
but over all, a good impact, and if that fails, a slug wrench. the other two options are a last resort thing