Nice Job on getting the rebuild done.
I suggest to anyone who doesn't have a compressor to not use any tool within the inner walls of the pistons. If you can get the tool on the outside of the piston and pull it out then that will save you from damaging the walls of the pistons..
I found through trial an error the best way to pull the pistons out without a compressor is using the following tools and method:
A long flat head screw driver and or small crowbar, cardboard, and 1 C-clamp (4 in or bigger).
You will need a table of some sort to lay the caliper half on and you will then C-clamp the caliper half to the table ( this way the caliper will not move at all). The pistons should be facing down towards the table.
Use the cardboard on the clamp side that goes to caliper so it doesn't scratch or damage your paint or the caliper itself. You then take a flat head screw driver or small crowbar and put it on the lip of the piston (using the caliper for torque) you push down and the piston will slide out. If it does not slide out or gives your trouble, you can push down 1 side of the piston at a time and you will be able to slowly shimmy it out.
The screws can be torqued to 60 pounds.
If you don't have grease you can use brake fluid to lube the pistons / seals when you push them back in.
The stages of my rebuild:
