Use a Plan for a Makeshift Armour to obtain the base outfit. It is dropped by the Warzone 4 boss, The Baron from Below.
By using the plan you knock together a makeshift armour out of wooden planks, rusty nails and leather rags.
Addon 1 (Shield and Weapon)
Use Crude Wood Planks to obtain the first addon. It is dropped by the Warzone 6 boss, The Duke of the Depths
You use the wooden planks to knock up a makeshift shield and weapon.
Addon 2 (Tinged Pot)
Use a Tinged Pot to obtain the second addon. It is dropped by the Warzone 5 boss, The Count of the Core.
You use the tinged pot as a makeshift helmet.
Besides the Makeshift Warrior Outfits you will also receive Cobbled and Patched Achievement which was implemented one month after the quest and outfits.