Your roaster drawer may have remained locked shut due to overheating, as a safety precaution. After the machine cools down you can follow these steps to open the drawer:
1) Unplug the machine, wait 10 seconds and plug it back in.
2) Wait 10 extra seconds, try to wobble / shake it a little bit to open the drawer -- the oldest trick in the book!
3) Once the drawer is open, try to remove all beans in the grinder section by turning the machine upside down (oh don't forget to empty the water out, and remove the carafe first dummy!) Make sure there are no beans in the drawer area, as they may have been the culprits responsible for wedging the drawer stuck in the first place!