My FSM tells me there's a spring clip that holds the inner (piston-side) pad against the piston but mine doesn't actually have that. There are no retaining springs or anything. The brake pads will pretty much just fall out when you pull the caliper. Make sure you don't simply hang the caliper from the brake line-it's relatively heavy and the flexible bit of line is breakable, especially if it's old.
Here's the caliper perched upside down on top of the rotor.