Canon 600EX-RT Battery door replacement instructions?

I have to replace the battery door on my flash (Long fall off a tall lightstand) and purchased
the replacement door direct from Canon USA.

However, it looks like it fits over a pin as a hinge, and, not sure how to get it out of damaged flash unit.

All the videos on Youtube are for Yongnuo door replacement... there's probably a message there.

Any hints?