Do you have the instructions that go along with the bracket and the harness? If so, there are no tricks beyond that. Also, your fairing may or may not have the optional horn kit.
If you don't have the instructions, let me know and I can send them to you. I have two Suzukis with Windjammers; a 1978 GS750 and a 1978 GS550. They fit, look, and function great on both.