Download the *.zip file
In Mac OSX with Dreamweaver, move the zip file to: /Users/< your username >/Library/Application Support/Adobe/Dreamweaver CS6/en_US/Configuration/snippets
After extracting you will see the folder 'Bootstrap_3.3.4'.
In the snippets panel you will see a folder: Bootstrap_3.3.4. Inside will be a templates & a components folder.