The part number required for the seal kit: 020 498 085 G
It comes with a new seal, a new plug and a new "C" clip.
It is important (as always) to take note of which way parts come out.
Let us begin.
*Volkswagon designed a tool to be able to compress the flange spring down in order to remove the C clip. When they did this they used a 9mm threading which means having to either find a 9mm bolt that is long enough and threaded the entire way up (good luck) or buying the VW tool. I used a nearly imperial equivalent in the tool I made.
-a 6 or 7 inch long carrier bolt with a 3/8 of an inch threading
-3 nuts with a 3/8 threading and 5/16 head size
-a washer
-a very strong piece of metal with a hole drilled in to allow the bolt to pass through
I recommend using a piece of metal roughly the same size as mine. There is an large amount of strain on it. It MUST be sturdy.
The car must be jacked up off the ground a good foot on the driver side. Use jackstands and proper safety when doing so.
1. Start taking the 12 point bolts off. Can't remember what size they are but it is not hard to figure out. Make sure you clean out the heads before you try to undo them. They will have a lot of gunk/dirt in them that will make them easy to strip.
2. Turn the front wheel to expose each 12 point bolt from the bottom of the axle shaft. When undoing them you need to have the wheel secured for them to be able to turn without the whole axle spinning. You will need to lower the car a certain amount to be able to slide the bolts past the CV joint boot. This is easier to do, as I have, with two people.
3. You now remove the bolts that adjust the camber on the driver's side wheel. This will change your alignment. It is important to mark the position of the allignment bolts to prevent needing to get it realigned... The three bolts are right under the outer CV boot, shown here
and a little more easily, here.
4. You should now be able to swing the CV joint and boot down away from the flange. It will most likely take some outward pushing of the wheel. It's a good idea to cover the boot in a plastic bag to avoid getting grunge from the undercarriage into the grease inside. I used a nylon rope to hold the axle shaft up and out of the way(for the most part).
5. The flange should now be exposed. The plug in the middle can be pried out with force because the kit comes with a new one. Be careful not to gouge the flange though!
6. The plug has been taken off and the inner shaft coming from inside the transmission is now visible. You can see the C clip in the shaft's lip (the open part is facing the left). The threaded part that you insert your tool into is the inside of the shaft. It will make more sense momentarily.
7. Insert two of the 12 point bolts originally pulled out. This will allow for some extra leverage when working inside.
8. The tool in action. Using the two nuts at the top, thread the bolt to the end of the inner shaft threading(it goes in approx. a centimeter). Now use the other nut to drive the piece of metal onto the 12 point bolts towards the flange. This will compress the flange allowing room to remove the C clip. CAUTION: THE FLANGE AND TOOL ARE NOW UNDER A LARGE AMOUNT OF PRESSURE!!! Be extremely careful when threading the nut down as a slip of the piece of metal could cause injury!
9. Now with the flange completely compressed, the C clip should be relatively moveable.
10. Using a pair of "C clip plyers" (plyers that work inverse to regular plyers) spread the clip and pull it out. Mine are shown here.
11. The C clip removed.
12. The flange is now able to be pulled out. Along with it will come the hefty spring and a cap on top of the spring. A bronze ring should come as well. Sorry I don't have a picture of it. But here is the opening after the flange is removed and as you can see from this picture transmission oil will probably pour out.
13. The parts lined up. From left to right(with replacements below):
Seal, Cap, Spring, Flange, (non bronze) O ring, C clip, Plug
14. Now reverse the previous steps. Insert the new seal into the opening, insert the bronze o ring, cap, spring, flange.
-Now the hard part... Thread the tool in with the seal and new C clip in the appropriate order.
-Continue to thread the nut down to compress the flange down allowing room for the clip to inserted. Using the "plyers" get the C clip back into the groove without spreading it too much. Spreading it too much will make it fall off when you go to release the pressure from the flange spring. Even if it doesn't fall off right away make sure it is on there tightly! If it were to come off while driving I'm sure it would not paint a pretty picture....
-The way I did it both times was spreading the clip and putting the closed end side on the inner shaft lip and then prying the open ends into the lip one at a time, holding the opposite end with my finger.
15. The plug back in with some silicone to keep a tight seal.
16. Now would be a good time to regrease your CV joint
. Insert the axle shaft back into the flange and align the 12 point bolts up and thread them in. 
17. Insert the allignment bolts back into their respective holes. Make sure to line up your marks carefully!
18. I lost a lot of oil so I decided to just drain the tranny and refill it with fresh oil. Lost probably a good half a litre in all.
And that should be it! Very time consuming, especially the C clip parts. But I'm sure more cost effective than taking it to a shop! If you have any questions or comments post or feel free to message me!
Hopefully we can make this a sticky or put it in a DIY section or something
-Matt
Nice write-up. The Beetles and buses had the same bolts with the 6-point head. It is certainly possible that someone used the six point bolts as they would fit fine. All the rabbits/jettas/vanagons I've messed with have had the 12-point.
Anyone know if a "speedi-sleeve" or "redi-sleeve" can be had for the gooved sealing surface?