Start the game from the beginning and invite your friend into your private game and progress through the first 5 minutes of the game on tell some bad guy bust through a door kill them and a man will appear in the busted down door for a conversation do not push a button and let the game set for 3 hours and the achievement will be yours, me and my friend did this well i went out and he watched TV, and when i came we both had achievement. We tried playing through but the game would always get freeze at the loading screen or we would lose connection so this is the quickest way to get achievement do to the fact that there are not load screens, no level ups, or equipment screens which the game doesn’t count as time played and you don’t have to worry about freezing and lost connections, also we taped are controllers in the up direction just to make sure and we used wired controllers and play and charge cords i hope this helps cause it sure helped us.
If you have any questions send me a message on my tag thanks.:)
(Update) This method can be done in offline mode with 2 controllers, just sign second controller in as guest and wait the 3 hours.