It's pretty straightforward. First remove the center u-joint. If re-using the u-joint, note the positions of the snap rings, journals and joint so everything goes back to its original location when reinstalled. Make mating marks on the drive shaft and center yoke, then remove the locknut and center yoke from the short, front shaft. Pull the outer metal mount and rubber off leaving the bearing exposed which you can then remove with a puller. Apply grease to the inside of new bearing and install the new carrier bearing assembly onto the front shaft. If the new assembly has a rubber dust/bearing seal on one side, install it with the seal toward the front shaft. Install the center yoke with the marks aligned and tighten the lock nut to 120-160 ft/lbs. Install the u-joint and snap rings. If installing a new greaseable u-joint, point the zerk fitting toward the rear shaft and in a position that mirrors the rear joint's.