Originally Posted by cameronmbecker

Ok, first and foremost I'd like to apologize for not taking pictures of this process as I went through it. I didn't realize how big of a pain this was going to be and that it would be worthwhile to document it. With that being said this IS a job that can be tackled by an individual with moderate repair knowledge and a decent set of tools. And of course a boatload of patience.

Difficulty: 7 - 8 (because of the horribly tight working space)
Time: Approx 5-7 hours (Mine took 13 because of all of the trial and error)

First of all i'll review the troubles I had, how I determined my problem was actually the starter, and then get into how to replace it in the most efficient way.

My problems started in a parking lot down the street from my house, drove the car 2 minutes and parked it. In and out of the store and then she wouldn't start. All electronics lit up like normal, fuel pump engaged but no start. Eventually I had my roomate come and tow me home with his Audi RS6. (Picture a 525 M sport being towed by a RS6) Funny to say the least. Anyway, tapping the starter motor with a small hammer got it up and running. I figured I would continue this until I found a good deal on a starter. (I also verified that it was the starter by checking the volts on the positive terminal of the starter motor when turning the ignition. If the volts read 12 or higher when the key is turned it's getting enough power from the battery and therefore will either be the solenoid or starter itself that is bad. Either way it needs to be pulled.)

In my research I found that the dealer recommends replacement via the bottom of the car. This will provide you with easy access to the positive and negative leads to the starter and an easier way to grip the starter for removal. Unfortunately you will have a very difficult time accessing the starter bolts in the transmission case that actually hold the starter in place. These are located on the top of the transmission case. I therefore, chose to approach this from the top. Now some of the youtube videos I found said that it is necessary to remove the intake manifold. While this will give you a better view of what you are doing it is not necessary and will create a large amount of work in the long run. I was able to do the swap without this removal.

First you?ll need to get some pieces out of your way, remove the interior air filters on the top left and right sides of the engine bay. These are fairly straight forward and just require a 12mm wrench to turn the plastic bolts and undo the latch on each side and the will come off easily. Next remove the filter housings that they latch into. There will be a 10mm bolt that needs to be removed on each side as well as 3 of those plastic 12mm bolts. These housings can then be simply pulled out. Now undo the 4 etorx bolts holding the sway bar in place. These can be loosened with a 3/8s and then taken off with a 10mm ratchet. The electrical lines will be running through the sway bar so simply push it aside, I would suggest undoing the rubber plug on the right side of the motor that holds the wire guide in place to gain more room to move the sway bar. I also found that undoing the positive lead to the starter from the jump start point as well as the Torx fastener were helpful as well.

Now if you have all of that out of the way you should have a small amount of access from the right side of the engine bay as well as from right behind the block. This is your work space?it?s tight, so be warned!

Somehow you need to undo the positive connection to the starter, this is a massive pain from the top but it needs to be done as there is a 2 gauge connection to the block from the starter that will not allow it to move freely once the bolts have been removed. (I did not know this and wasted hours trying to get the darn thing out!) I suggest feeling the starter and following the positive lead you have access to down to the bolt, then loosening with a 13mm ratchet(guessing here! But fairly sure it was a 13!) make sure you pull both positive leads off the starter! The one to the jump point can now be removed entirely so it is out of your way. The negative lead can be left alone for now. Now to undo the two starter bolts you?ll need a 3/8ths wrench and in my case a 10mm ratchet style. I fit the 3/8ths over the bolt and used a pipe extender to turn them the first few turns until they were loose. (if you use a 10mm you will strip them!) Once they are loose use the 10mm to ratchet them all the way out. When both bolts are removed the starter will now only be held in by a mounting pin in the upper right corner. You should at this point be able to rock it back and forth until it is released from its mount. Once it is free move it into the open space to remove the negative lead.

Now simply(relative term) reverse the process. The hardest part is removing the bolts, both that E12?s and the positive lead take massive amounts of patience and being a contortionist is definitely useful!

I wish I had pictures to help like I said but a little research and some logical thinking should get you through this one. Hopefully this is somewhat helpful as well. Cheers!