Here's following a step-by-step installation Guide on how to install the MCC mod or mission version in Arma 3

mod version: Edit

1) Download the mod here

2) extract the donwloaded rar file to your desktop

3) move the created folder to /common/steamapps/Arma3

4) make sure it now looks like this: ...\Steam\SteamApps\common\Arma 3\@mcc_sandbox

5) add the following startup parameter: -mod=@mcc_sandbox

5.1) if you already use other mods, add it like this: -mod=@other_mod;@mcc_sandbox;@yet_another_mod

6) start up arma 3

7) enjoy!

mission version: Edit

1) download the mission version here

2) place the mcc_sandbox.altis and mcc_sandbox.stratis in the mission folder

3) start up arma 3

4) go to multiplayer, host a new session and press play

5) enjoy!

-- under construction -- Edit