Well, you need two accounts (RaF is amazing for this as the second character following will gain good exp quickly)
The quest: Crossroads Caravan Pickup gives you a gun to kill the boars attacking; but the gun can shoot other mobs that are in range. If you're in a group the person not on the caravan will gain exp for those kills. It one shots them and it's easy.. That's pretty much it. When you complete it you can drop the quest and do it over and over again. Have fun.