I'm not very familiar with the W202 cars, but I think they were built AFTER the M103 engine was out of production, at least for the 124 cars use.
I expect that the C280 is the M104 engine which as far as the water pump job goes is similar.
IF it is similar to the M103 in this area, there are a few simple special tools that you will need. There is a 1/4" size bent rod that is used to hold the fan in place while loosening the center bolt with a special short allen socket. The 1/4" bent rod you could make out of something if you had to. I don't know about the allen socket. There is limited clearance between the fan and the radiator, so you really need the special short socket. Again this information applies IF it is similar to the 124 with M103.
Your best bet is to find a manual or a CD. I expect that there is not a lot of magic involved in this job beyond removing the fan and knowing how to correctly tension the drive belt when you're finished. BTW, I would plan on replacing the drive belt while you're there. Also inspect the tensioner mechanism and be prepared to replace it if necessary. I would not replace the tensioner if it is in good shape as a preventive maintenance step.