tazzboy,
If the pickguard is loaded with pickups, cap and pots already wired, all you have to do is solder the hot lead (white) from the jack to the center tang of the volume pot, and solder the ground lead (black) from the jack to the back of the volume pot where you'll see other ground wires soldered. Check a Strat wiring diagram to be sure. If you're handy with a soldering gun, this should be a snap for you. Of course, you did make sure the screw pattern on the new guard lines up with your Strat.
Good Luck,
62stratfan
http://www.seymourduncan.com/support..._1v_2t_5w.html