All four of the drain plug magnets looked like the left side of this one. I'm not trying to re-write anything since there is good info over at nissan4wheelers.com, but I'll include some pictures and hopefully encourage you to change your fluids if they haven't been done lately. You will need a 1/2" drive ratchet, with a 3 inch extension for the front differential, a pump to get the oil out of the jugs, and some thread sealer (not locker) would be good. I would recommend breaking the fill plugs free first, before the drain plugs. I put some PB blaster on all 8 plugs the night before and they all broke free.
This also resolved some strange noises I was hearing in the driveline at lower RPM's, mainly in 2nd gear, under a load.