The arrow is pointing to a thumbscrew...unscrew that, "move the feed lifting crank down so that the thumb screw will enter the proper hole. Having inserted the screw in this hole, tighten it firmly. The feed is thus rendered inoperative and will not interfere with the free movenment of the work. Move the stitch regulator to the neutral position in the center of the slot."
~quote from the manual~ ^^^^
You can either use any short shank darning/FMQ foot, or use the machine with no presser foot at all....either way will work.
Make sure that the machine is unplugged when you're not actually using it...it's the type (direct current?) that if it's plugged in, it's on....