For those that bought the addon online / over steam, you can find the manual here: http://cdn.steampowered.com/Manuals/5773...1303163985

Was just about to ask if anybody had a link to the PDF when I found it myself.

Note: For future reference, if you are a steam user you can go to the store page of the game in question, and down the right hand column there is a "View the Manual" link.