Find the available seats you would like to pick. Note that grayed out seats are unavailable. If you roll your mouse over a seat it tells you the row and seat number and the prices available for that seat.
Click on the seats to select it. If there is more than one price level for the seat then you will be asked to choose a price (see animation). If you are senior and they have specific senior seats, make sure to take advantage of the discount.
The selected seats will show a checkmark on the floor plan, and your cart will be updated with the selected seats and prices.
If you would like to remove any selected seats then you must click again on the selected seats in the floorplan and that will remove them from your cart.
Click the orange Checkout Now on the right after you have selected your seats to go to the checkout.