To use BCCFS you need to have BLT installed.

BLT:
https://paydaymods.com/download/

Instructions on how to install BLT can be found on that page as well.

After BLT has been installed (I.e. dragged and dropped into Payday 2's game folder), you're ready to get started with installing BCCFS.

Download the latest copy of BCCFS from Paydaymods.com

PDMods page:
http://paydaymods.com/mods/157/BCCFS

Direct download link (.zip file):
http://download.paydaymods.com/download/latest/BCCFS

Once you've downloaded the file, it's as easy as dragging the entire "BCCFS" folder contained in the .zip file, into the newly created "mods" folder provided by BLT.

Any future updates to BCCFS will be automatically downloaded for you, by BLT.