Step 5 - Insert the sliders back into position making sure the seal is tight with the housing it connects to.

Step 6 - After removing old pads, take off the anti-rattlepad that sits on the outside, apply more Copperslip to the back of the pad at the 2 contact points. The Copperslip will help eliminate pad-rattle as the pads wear down. Put the pads back into position as the previous ones were.

Step 7 - Using the fork of an open ended wrench, wind the piston counter-clockwise into the housing. The front piston can simply by pushed back in with a G-clamp but the rear piston shown below has a cross section which lines up with a nipple on the inside rear pad making up part of the handbrake mechanism.

Once the piston is in place, re-attach the 12mm bolts to hold the caliper in place, then insert the 10mm bolts holding the spray guard.
You are then back to:

take it easy with the pads while they bed in, take a drive somewhere to start them off but avoid heavy braking. You WILL experience less stopping power until the pads have bedded in.
Sorry for the poor quality pics, I need to get a proper digi-cam instead of borrowing the one from work.