Yes it's very simple you just run back to the rental facility and drop the car off, then you pick up the new rental which will be another car. I have done this a few times before.
I just use the Kiosk and it takes about 5 minutes total to do.. then I am off to enjoy the rest of my trip. I saved about $125 doing it this way.
I think I'm going to take a pass on this one. Just signed up and checked the rate on a full size car. From 08/14/11 to 08/19/11 after both discounts ( 10% and the coupon code ) $333. Way to high.