.EXE File:
To use the mod, simple open dark souls. Open the mod and press the checkbox.

.CE File:
You will need to install cheat engine to use this file:
http://www.cheatengine.org/
There are tons of tutorials online how to use the software, but i will put a simple step-to-step here:
Open Dark Souls
Go to "File->Open process"
Find DATA.exe
Go to "File->Load" and find the .CE file
Activate the "XLive Cheat Detection Disabler"
Press the checkbox on "DISABLE Xlive Cheat Detection (Version 1)"
Press the checkbox on "DISABLE Xlive Cheat Detection (Version 2)"
Turn on the checkbox on "Aggression Mod"
Thats it