There is not much tolerance for turning before the rotors are too thin.
The rotors are not real expensive, you will be better off replacing them.
Are you sure the problem is the front rotors? It is difficult to determine if your problem is in the front or the back. It will be difficult to turn the warp out of the rotors, and even if you do, they will probably be too thin afterwards.
Best of luck,
'01 C Class, Six Speed
'84 Euro 240D, 523K miles
'88 300E 5 Speed
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