Start Chapter 6-2 with only the bare essentials you need to survive. It is recommended that you only bring one good handgun or shotgun weapon (for example, fully upgraded M92F, Jailbreaker -- because ammo will be more than plentiful) each for Chris and Sheva. If you feel you are proficient enough with your chosen weapon, you can take only one weapon for your chosen player and leave the other character's inventory completely empty so they can carry ammo and herbs. Get through the cutscene and interactive sequence. Once inside the tanker, scavenge any ammunition and herbs you can find. Do not forget the two chalices in the lockers for extra money. Once you are ready, head out to fight the Uroboros that Excella has now become. Do not finish her off until you have filled your bags with all the ammo and herbs you can carry. Begin by shooting the orbs on the ends of the tentacles until they are gone. This will prompt the Boss to start shooting small Uroboros creatures at you and your partner. Stay on the lower level (where the satellite aiming gun is located) so that you can command your partner to quickly pick up ammo. Begin shooting the small spawns the Boss is tossing at you, and each one will randomly drop some sort of item. It is best to separate the types of ammo each person picks up. For example, have Chris collect all the shotgun and pistol ammo while Sheva gets all the grenades and herbs, etc. This will help maximize space in your inventories and allow you manage the space efficiently. Repeat this process and dodge the Boss attacks (they are indicated by a context menu), and shoot the small spawns to keep collecting ammo and herbs. They commonly drop handgun and shotgun ammo and plenty of herbs and incendiary and hand grenades. Doing this for about five to ten minutes will net a large amount of ammo and herbs because the Boss will continuously spawn the small monsters until it is defeated. Once you are satisfied with your farming run, finish off the Boss through whatever means you desire and finish the episode for some quick exchange points. As long as you do not die and keep your firing accuracy up, it should be an easy "S" rank on practically any difficulty. Repeat the entire process if desired.