I will try to explain to you with my bad english, let's see with you will understand.
The front splash is that one that has an extra hole. This big hole is to fix a plastic clip that holds the lateral plastic guard.
To install the front guards you will have to take off the original screws (2 screws) that hold the internal structure of the fender.
The red circles are the original screws.
The yellow circle is the plastic clip.
Under the guard you will use one of the screws that came whit the guards.
In my car i had to do a small hole on the lateral guard to fix the screw.
It's not hard to do, stay cool.
The rear is easier to do.
You will see in the rear bumper the exactly place to do a small hole to fix the screws (2 screws that came with the guards).
Do a small hole with something pointed, you wont need to drill, just open a small hole with sometinhg pointed and complete the process tightening the screw.
Under the rear bumper exists another point to fix the guard.
You have to take off this original screw under the rear bumper, place the guard in place a tight the 3 screws (2 that came withe the kit and one that is under the rear bumper).
My english is very basic, i don't know specific words to tell you with details how to do it, but it's not dificult to do.
Try to do the job and you will see how easy it is.
Hope my words help you to do it.
Good luck.