First, the writer is obviously being clever by saying it in a way that it almost like poetry--"get," "guts," "gadgets" starting with the same letter, and "get" and "metal" having assonance in the "e" sound.
"To get at" and "to get" mean different things. "To get at" means "to reach, to access." "To get" means "to take, obtain." Before they can get the metal, first they need to get at the place inside the device where the metal is.