Dont know if someone has mentioned this yet but this is what me and my friends used to do when we were in 7th period for 3hrs after school.

Materials:
A card (I used a gift card) or a Paper Clip
NO MONEY!

Steps:

1) Use the card or paperclip and wedge it under the door. Flip it towards your hand in order to open the little door.

2) Once the door is open reach in and grab any thing you want from the first row, just dont drop it.

3) Enjoy your free beverage. Might not be what you were craving but it was alot cheaper.

We used to take the entire first row so that everyone in the class could have one.