While your working on the tailshaft it might pay to check the uni's aswell
if they resemble below, old and missing dust boots it's time to do something about it.
here's how to do them all with a flat screwdriver, a hammer and a vice.
Firstly remove the four retaining clips holding the cups in place carefully with a screw driver, don't really want to be stabbing yourself.
If they're jammed in and won't budge you may need to tap the cup inwards to relieve the pressure as shown.
it's an idea to spray some crc/wd40/inox etc to penetrate in and aid in removal then follow through with hitting it with a hammer in the spots as shown below
so with minimal tools this can be accomplished, next it's time to put the new uni's in
don't use a hammer to drive the new cups in as this can dislodge the needle rollers and cause lots of problems.
firstly insert the + section
now place the cups in position
if you don't have the proper tools like a press i've found a vice will do the job nicely.
once in the vice do it up and make sure they're going in perfect and not angled
if it's taking alot of pressure doing up the vice (which it shouldn't) if they're going in square and straight you may need to give the jaws a gentle tap with the hammer to move them, don't do it up with as much pressure as possible and try this or you'll most likely break the vice.
rinse and repeat 4 times
once the cups are in place make sure the circlips are seated correctly and give each part of the tailshaft, yoke etc next to the cups a quick tap with the hammer and make sure they all articulate freely.