To change the variables you want is easy enough.
If you want BAR to fire faster change the rate setting.
If you look at all the words like
DM Ammo: 20 well chanign that will give you more ammo in the clips etc:
Just takes a while to figure out what each means.
I use
http://www.textpad.com to edit all SCR and TIK files very good program and free :)
kdjaC