I wouldn't call the link a spoiler but some people might so fair warning, possible spoilers behind the link!!!
You can also find out how to open the door at JK Rowling dot com at The Leaky Cauldron.
That said, the last step won't work for me! I can't pick up the key D:
YAY! I can't wait for next year...it better be out next year and it better be better then book six. I re-read book six, it kinda grew on me but it's probably my least favorite of the books and my least favorite post-GOF for sure! Book seven is supposed to be shorter then HBP!!! I think it should be as long as OotP...or OotP and GOF combined! Ah well, I just hope it's good.