Yes...it's an easy job. But I'm guessing with my 99. Assuming much hasn't changed on the 2003.

As far as tools, ordinary metric socket wrenches will be all you need to complete rear pads. You need a #40 torx socket to do the fronts.

Calipers need to be moved out of the way of the rotors to remove the pads...thus, rotors can also be replaced at this time.

The pads are a slip fit onto the calipers via metal clips on the center of the pads. Pull out old ones and press fit the new ones.

I went with Textar pads (on all my vehicles)...quiet, and less dust than Pagids (which IMHO are notoriously squealy).

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car