Easiest way to get this is with one friend who has one extra controller with a second account, and you having a second controller with a second account.
The quest can be taken from Pickle who is located in the area to the right of the fast travel station in Outlands Canyon. I don't remember exactly when you unlock the quest, but it's sometime near the end of the main story, second to last mission or something like that.
After picking up the quest, go to the fast travel station and fast travel to Titan Robot Production Plant and turn to the right and go through the map exit to your right to Titan Industrial Facility. This is just to save time. Anyway the quest is pretty straight forward and doesn't need further explaining.
Do this on normal mode for speed.