You're not supposed to kill anyone. You're just supposed to sneak into the tank hangar. Avoid the guards and use the stairs in the NE corner of the map to find a hole and crawl through it.
Metal + Tools = Weapons
tool + metal = weapon.
tools+metal=weapon,weapon+human=hunter,hunter+weapon=warrior
tools+metal=weapon,weapon+human=hunter,hunter+weapon=warrior
Full Metal Alchemist
tools + metal =weapons; weapons + poison = poison weapon
tools + metal = weapon
metal and tools=weapons
Metal Storm
Once a powdered metal has sintered, it is not possible to return it to the powdered metal state without grinding, or perhaps applying high energy ultrasonics.
unless the weapon has been rendered unusable, it would still be a weapon
you don't get the weapon parts. You find documents in missions and extra ops to build your weapons.