The repair consists of removing the shaft either way, boot repair or shaft replacement. The work is easier just to replace the shaft - you don't have to do the boot repair. If you decide to just replace the boot in place, if you can find such a boot for your truck's axle, make sure there is no existing damage and no dirt or other contaminant inside the joint before proceeding, or you will soon be replacing the axle anyway. Boot replacement is a very dirty, messy job, at least that's my experience. If you can afford the new/rebuilt shaft, I wouldn't even consider boot replacement.