What you bought was the front valance. It should mount up with relatively little difficulty, however, you will need to get a spoiler to cover it. The only spoilers that will fit with that particular valance is the factory 'es' or 87'is' spoiler or the Racing Dynamics front spoiler that looks like the es/87'is spoiler.
Honestly...without the spoiler, the car will probabbly look quite odd. Also, you will need a different kind of fog light than the ones you have mounted to your bumper. They use different brackets to mount to the valance.
If you need them, I'll be happy to supply you with the part numbers.