Use the Construct Activator anywhere in the target areas. Once summoned, the JKG-77 will follow you around and, when he smells one, will run over ("Target Acquired!") and dig it up. Use the Dirt Pile and, usually, a Cursed Vigilant will appear. Kill him and loot him to get your Blessed Weapon. Occasionally you will simply find a weapon and no Vigilant will appear.
NOTE: The JKG-77 is a tool, not a pet. He will not fight for you.