I used a 36mm socket and 36" 3/4 drive breaker bar from pa for about $40-$50. Took that and a torch plus a can of pb blaster to get that nut out. To remove the unit bearing after the nut and three 13mm twelve point bolts were off, I did the bolt trick to get the unit bearing out with ease. You spin the axle till the outer shafts ears are parallel to the ground, place a bolt or socket that's long enough between the outer ear and inner "c" and have a buddy turn the steering wheel left until the unit bearing pops out. (if it's the passenger side bearing that's gone).
This was on a xj Dana 30, not sure if it will work the same on a vacuum disco. You might want to change the u joint while you have everything open too, seeing as it's only another $35.
FYI, partsource wants $165 for a Dana 30 unit bearing.