It is very easy to put on, I put mine in 2 hours with sanding, a little cutting and drilling. Basically you want to transfer the holes on to the new bumper. Locate the screws on the old bumper and make new ones on the new bumper. There should be two screws on top and one on each end. I would recommend using washers (Stainless steal, or galvanized) on top, between and underneath the bumper to give it a less chance of cracking while installing.
The bumper will look crappy with the mesh that they supply with the bumpers, I honestly like no mesh at all. Your bumper looks really good when you paint the lower part lip black, it looks bad in a solid color unless you go white.
I took some quick pictures and measure the holes for you to give you a better idea where they SHOULD be located. REMEMBER MEASURE TWICE, CHECK IF IT LINES UP, DOUBLE CHECK EVERYTHING AGAIN & DRILL CAREFULLY.

And little teaser of my bumper being cut and chopped. I am in the middle of putting a custom lip on it (Brown color). With the springs that I will be installing a few months from now, the Evo4 bumper would not have no clearance at all. I just put some hardener on back of the bumper to make it more stiff, because when I cut the lower end, it lost most of its strength. Will give some more pictures when it is done:P