Find all ten of the scavenger hunt areas and go through the portals at the end of them to get the directions. You must get the full set of directions to get this achievement.
This is pretty tough; the last two in particular are amongst the hardest things to do in the entire game. Good luck.
http://steamcommunity.com/sharedfiles/filedetails/?id=739225...http://steamcommunity.com/sharedfiles/filedetails/?id=740633...