Just replaced the fuel filter and power steering fluid/filter on my 94 C280 during the weekend. Both jobs are quite straight forward and simple. However, for the fuel filter, you will always get some gas spilled on the ground more of less.
For the power steering fluid, I disconnected the tube from the radiator back to the power steering fluid reservoir, lifted two front wheels, and had a helper (who is my lovely wife) turn the steering wheel left and right to get the old fluid out of the system. The only problem I had was that I only bought one bottle (1 qt) of fluid and it seems to need a little bit more to get all the old fluid out.
Let me know if you have any questions about these two simple maintenance operations that I can answer.
Harry (94 C280)