C280 Water Pump
The water pump is not that difficult to replace on the C280. You may need to remove the radiator shrowd from the inside to get room to remove the pulley of the water pump. Additionally, make sure you loosen the belt tensioner bolt in the middle of the tensioner before releasing the tension from the tensioner bolt. This tensioner bolt runs vertical and it sticks out behind the Power Steering Pump. You have to release these two items before you remove the belt from the Power Steering Pump.
Let me know if you have any further questions.