This method works best with the brake caliper and hydraulics still connected. By squeezing the brake lever, one pot will come out first, leaving the other one still stuck.
By cutting two equal lengths of quarter inch steel, long enough to cover a pot and clear the caliper, and around 2 to 3 inches wide, depending on your requirements, you can gently, and without pressure, clamp the pot that easily comes out, so that all available hydraulic pressure goes into removing the stuck pot. As it comes out, loosen the screws on the clamp so that the piece of steel between the pots ensures that one pot does not "pop" out before the stubborn one is far enough out to be extracted manually.
http://mishpics.yolasite.com/010.php (http://mishpics.yolasite.com/010.php)
I do not know how to upload pictures, so the link is above.
I hope this helps out those who do not have access to an air compressor.
cheers