The repair is done with the seat in the car.

There is only one headrest guide per seat... only one post is used for powering the headrest.

I don't know how bad your back is (mine isn't perfect), but removing the seat back is more frustrating than anything. What makes removing the seatback difficult the first time is the fact that there is a lot of "sticking" between the surfaces that need to come apart. I swore that the seat back would break while I was removing mine (it didn't). One tip is to work from the bottom and have the mating surfaces roll apart. Keep tugging and pulling at either bottom corner. Once it starts moving, you're home free. I kept tugging and pulling for at least a half hour before anything happened. I just want you to be mentally prepared for this job. It'll happen.

In my case the headrest guides were broken on each seat. One had the rack broken - no shadetree fix for that, I had to buy a new assembly. On the other one, the gear housing broke. (Buy one - may as well buy the other). I didn't try, but I don't see why it can't be fixed with a hose clamp. If only the housing is broken on yours, you may get by with a no-cost fix... just your labor!

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95 E320 Cabriolet, 159K