Just a simple question?

How do install/inject hacks into dayz?

what things do i need?

Check out Lystic's thread "Darky Script Executer Version 1.0 [Darky.Hax]", you can use this program to execute SQF scripts into the game. It comes with a bunch of premade scripts but it of course allows you to create and use your own too. There are also a few private hacks out there that offer various things like ESP, aimbot, teleporting and script execution for DayZ SA at this time too.