He does the front wheel for easy viewing.

  Terminology
  Flat Mount. (Doesn't make any difference)

Insruction
 - remove clip
 - undo 3 mm hex head
 - pull the pads down thru the bottom
 - turn barrel adjuster all the way in (off)
 - turn 3 mm screw anti clockwise
 - put spring on new pads
 - line up for pin, screw in 3 mm
 - put clip on end of pin
 - refit wheel

He talks about using the barrel adjuster to make up for wear, but the other way would be to readjust the pads.