I found it:

http://www.peachparts.com/Wikka/W210Evaporator

it is an EXCELLENT write-up and I'd suggest you print it out and look it over carefully. You might consider doing it yourself, though it looks quite daunting and a bit scary it will likely save you a grand or two.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz