I have the driveshaft out, both parts, and have renewed intermediate bearing and support. Will install new front and rear flex discs.

Question is how does one torque the driveshaft coupling nut to factory spec? It's very hard to get to and the nut is 46 mm.

When I removed the driveshaft the two parts just came apart. The coupling nut was not torqued at all as far as I can tell. I'm thinking it may be ok to just hand tighten as much as I can.

Just get it snug where the front driveshaft will still slip front to back.