Ok, I haven't looked at the P5s brakes specifically, but here's how to bleed brakes:
On the back of the caliper, there should be a bleeder valve. It'll probably have some rubber cap on it, but just take that off. Then there will be a screw. You'll need two people. Have one person take a wrench that fits the screw, and loosen it (just enough that it's, well, loose). Then have the other person step on the brake inside the car. Watch out 'cause brake fluid is going to shoot out at this point. Then, while still holding the brake down, re-tighten the screw. Let off the brake. Repeat this process until there is no air coming out of the bleeder valve, ie solid fluid.