The Legend of Moe and Marley
The Hardest mission in the Arid Hills non story wise anyway is pretty hard considering all the skags and two bosses at the same time.
Moe Killed 0/1
Marley Killed 0/1
Head to the way point and keep the skags in the area alive for a second wind if you are down make thing easier to deal with.
Get out either a Shotgun,combat rifle,Rocket launcher or SMG for this mission. Start by killing Moe he likes to charge but Marley doesn't.
After killing Moe kill Marley then head back and turn the mission in