There's no trick. Just open the tiny set screws in the aluminum collars, slide those off. Then take a plastic hammer an carefully tap on the axle (first from one side, then from the other when the first bearing popped out). Same trick works for the rear axle as well.
Btw., if you have the version with the Shimano free-hub you could upgrade it to a XTR or Dura Ace one, that will make your rear hub considerably lighter...
When pressing in the new bearings, make sure you apply pressure on the outer race ONLY (otherwise you'll ruin the fancy new bearings).
I have a set of NOS Nuke Proof Atom Bomb hubs and the rear hub takes the R6-2RS bearings, didn't find SKF bearings in that size so I got a pair of FAG precision bearings instead.
The original chinese bearings on those hubs are crap. My front hubs use oversize 61804-2RS1 bearings which I got from SKF. You probably have the previous version of the Atom Bombs that use the same size bearings in the front and back. In general Nuke Proof hubs are very easy to work on. Now keep your fingers crossed that they won't de-laminate.