Ramps in some side-loading minivans pivot to a stowed position so that it is out of the way when you do not need it for wheelchair use. Placing it in the stowed position allows ambulatory passengers (those who can walk) access to the rear of the vehicle. Once you stow and release the ramp a few times, it will be a fairly simple procedure; but at first you may have to fidget with the system to figure it out.
I found that the easiest way to work this was to unscrew the knob just enough so that the metal plate would rotate out of the way. This way, I did not need to find a safe place to keep the knob in the vehicle (or god-forbid, my coat pocket or purse–I would never find it again!) and it could be left in place as part of the mechanism in the L-track system. One word of caution on this–leaving it in place may cause a tripping hazard, so if passengers may step near this on the floor, be sure to take the whole mechanism out.