Several years ago I did this job on my 240d, which was an '83. At least with that car, the trick was that the suspension had to drop down a little further. As I remember, the trick was to unbolt the shock absorber? which let the hub carrier drop far enough so that the half-shaft would clear. Or something like that...
What I can tell you for sure is that there's a trick to it, and it wasn't in the Haynes book I had, and it took me two calls into a Mercedes dealer before I talked to a mechanic who told me what the trick was. Hopefully someone else will either confirm my recollection, or give you the answer for sure.
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