Take the bumper off the car and set it on a bench. Put the lip up on it to see if it is too long, which it most likely will be. Cut down exactly from the Center and repeat the first step too figure out how much to trim off of each side. That is how I have seen it done on Late 3rd gen Preludes

This is what I found for the Lude.

It's not too bad really...It's alot easier with the bumper cover off too!!

The sides fit perfectly after you cut it in half.

Here are the steps I used.

1. Cut it in exactly half.

2. Get a friend to hold both side on so the middle over lap and mark the end of one of the pieces where it overlaps the other and that is where to cut.

3. Cut the part out of the middle.

4. Use self tapping sheet medal screws to screw it securly to the bumper cover starting from the outside and working towards the middle (I used like 1000, lol) The more the better!!

5. Where it's cut in the middle, use fibreglass on the back of it to mold it together. Doesn't matter what it looks like, you won't see it. Goop it on!!

6. Use a little bodyfill or fibreglass resin fill to smooth out the front and then sand smooth.

7. Use spot putty to do the finishing touches.