Since yours is extended cab, and if the PSD also is, then shaft will swap over directly. You'll want the PSD rear axle yoke to avoid running a conversion joint, so plan on taking 1-1/16 and 1-1/8" socket (forgot which size the pinion nut is, but it's one of the two) and 1/2"-drive breaker bar and ratchet and cheater pipe that fits said ratchet.
If the PSD is regular (short) cab you'll be using a section of its 1-piece shaft to lengthen the front half of your existing 2-piece shaft - you'll be cutting the rear slip yoke (the one that goes thru the support bearing of your front half of the shaft, then cutting the rear off the PSD shaft so the front section is longer that your factory front tube by whatever inches are needed, then you'll be welding this longer section onto your factory slip yoke. Be warned this only works if both driveshafts are the same diameter, so measure both yours and the PSD one before you take the PSD one home. If the PSD is a dually truck then it may have a driveshaft of larger diameter than what your truck runs, in which case splicing will not work.
If the PSD is a crew-cab (4-door), it will have a 2-piece shaft like your truck does, but IIRC the front half will be longer than yours. In which case you just cut the PSD front yoke off, shorten the tube as needed, and weld the PSD front yoke back on. You will again want the PSD axle yoke to match the PSD shaft rear U-joint. And again watch out for driveshaft tube size, if the PSD starts at 3" at the front yoke but then goes up to 3.5" or more a few inches after it then after you cut it you'll end up with a 3" yoke slipping into a 3.5" or larger tube, that's obviously not gonna work. It's ok if the rear half of the PSD shaft is like that tho, as long as it's the same length as yours you won't be modifying it and you'll be running it as is regardless of diameter.
Make sense?