I use the Valkyrie Injector(google it) and after you download it, extract the content to a folder using WinRar(google it)
All you have to do is where it says "Process Name" type in "AVA.exe" (must be all caps except for the .exe part)
Click the "add" button to add your .dll hack. You can add as many hacks as you want, it will inject all of them.
Click the inject button, and when you start up AVA, it will automatically inject and minimize to your task bar
"Thank" if i Helped
P.S. There are currently no "FREE" A.V.A hacks. Maybe some simply ones that don't need to be injected. But there security(GameGaurd) is tough(or so i've heard)