There is no need to change the rotors unless yours are worn below the minimum allowable thickness. If you don't have a significant ridge at the outter edge, they are probably fine to continue using.
The brake pads are changed easily without removing the caliper. Take a look at the DIY article link at the top of the page.
Does the C280 have pad wear sensors? If so, make sure you get new ones. Also have some anti-squeal paste on hand.
Experience is something you don't get until just after you need it.