Normally I don't start threads for these, but it's been requested enough so I figured I'd make one and redirect everyone here.
To use, download the zip file and extract the contents. Inside the chernarusredux folder, you will see a folder called x. Place this folder in your mission root folder (the same place where the mission.sqm is) and ALiVE will recognize the index automatically. This can be done for missions for the time being so you can have ALiVE/Chernarus compatibility, until it's included officially within ALiVE in the next update (which will mean you won't need to use the x folder in your missions anymore).