you'll need to remove the lens / reflector assembly to get the bracket for the screws. Read the directiona and it'll show you how to put them together (you don't remove the screws from the brackets, just loosen them enough so it'll slide together)
Did you use the stock wiring harness, or the one that came with the piaas?
Did you test the lights before finishing the install? Get yourself a test light and make sure that there's power from where you're trying to get it from. Start at the battery, trace along the power cord and check everything.
If all else fails pull it apart and start over.
Trust me, you're gonna love the lights, as well as everyone behind you. But anyone in front of you or coming towards you are gonna be blind