The red/pink goo is Anti-Squeal, which when put on the back of the pad, can later prevent high pitch squealing. It takes a while to dry, so one might put a light coating on the pads before beginning....

The pad goes into the carrier, inside the channels defined by the clips, and up against the retracted piston. One can see here the tabbed-end of the pad, in the carrier's channel, and the clip peeking out, keeping order....

The business end of the new pad.