If you don't know how to use it, how is that a problem. Anyways, here's how to make it work.
1.Download the hack
2.Extract it
3.Open injector (make sure you run it as admin)
4.Add the .dll
5.Start Combat Arms
6.Hack using the numpad (on desktop)
If that doesn't work:
1.Try a different injector
2.Try a different hack