Well, I just did mine, and after reading the previous post, noticed one ommission. There is an arched metal tab on the outboard pads that faces the rear of the car. To get the caliper back on, you have to start with this tab (spring) being stretched so as to allow the thing to rest against the underside of the pressed on metal slides. You will see what I mean when you do it. I too took about 1.5 hours studying/replacing the first side and 20 minutes doing the other side.

I relieved the caliper pressure with the bleeder screw (10mm wrench). Piston went in very easy then. The only other tool needed was the Torx bit.