I dont understand whay you've taken the caliper apart to take the pads out...
You only have to undo the bolts that hold the caliper to the hub...
bang the whole caliper of with a hammer and then tap the pads out...
to push the piston in on the front use a g clap or handle of a hammer if there not to stiff. On the rear the caliper piston is differant you need to use long nose pliers to push and screw clockwise.
dave