Sign in to your Redbox account, or create one. Find the movie you want on the Redbox site, then click "find a Redbox" to find the nearest location with that movie. Click "rent" next to a location.
Verify the information on the next screen. It will include the title of the DVD, the pick up date and time, where to pick up the DVD, the credit card used for the rental and a total charge. It will also give the letter of the machine with your DVD if the location has more than one machine. Duplicate the process to reserve more movies.
Go to the Redbox location during the pick up time window. Touch "online rental pick-up" on the Redbox screen, and swipe the same credit card used for the rental. The DVDs will come out the right side of the machine.