I'm going to solder in a SD '59 into my new PRS (in the bridge), but I'm not sure how to solder it in. I've checked the wiring diagrams on the Seymour Duncan site but they're not helping me since their diagram is for a 4-conducter pick-up and the '59 is a single conducter pick-up. The guitar is S/S/H, one volume, one tone, and 5-way switch. I am confused.
use the wiring diagram from the SD site, but ignore the red and white wires that are taped together (as your pickup doesn't even have them). For the hot/ground wires, the outer cloth part of the wire is the ground. Treat that as the green and bare wires in the diagram. The inner wire (push back the cloth sleeve to get to it) is the hot wire.