WarHammer 40K - Chaos Gate

First, go into the Data file in the game directory.
Then, you can edit any of these files to change certain
aspects of the game, such as:
Names for both sides, weapon statistics, experience
awarded for kills, vehicle statistics, Psyker power
statistics, and more! All you have to do is edit the
files.
These are the ones I have found most useful:
Accounting.dat - Experience
SpellDef.dat   - Psyker Powers
VehicDef.dat   - Vehicle Statistics
WeapDef.dat   - Weapon Statistics
UltNames.    - Ultramarine Names
ChaNames.dat   - Chaos Names
Note that any changes you make may effect Chaos as
well, so be careful, especially with the weapons!