After downloading the mod, use a program such as 7zip or WinRAR to extract the main folder of the mod.
Navigate to assets/mod_overrides. The assets folder is supposed to be in your game's installation folder (don't know where that is? click here). Create the folder if necessary
Move the main folder of the mod from step 1 to the folder you navigated to in step 2.
CAFCW is needed for custom optic support.
The ACR submitted to the ICC does have built in support for Heartbeat Sensor, because I anticipate nostalgic MW2 players wanting to rock the ACR with babby monitor once again.