Do not use a pry bar! Simply push in on the trap door handle (gray tubular handle) and pull up on the locking mechanism (the flat handle with black rubber grip). By pushing in on the door handle, you are relieving pressure from the locking mechanism, making it much earier to open when full of debris. If this does not work, then the trap door mechanism is probably bet, possibly due to the use of a pry bar, etc. to force open.