Five years ago a Philippine Airlines A330 was hijacked by a mentally deranged person. Aside from the obligatory gun, he also had a homebuilt parachute. At some point, after passing a collection hat around for money and jewelry, he demanded to be let off the plane. The flight crew was only too happy to oblige--a member of the cabin crew opened the rear door and allowed the hijacker to jump off at 6,000 feet or so. Shades of D.B. Cooper! Except this guy, or what was left of him, was found in a muddy river bank.
I am not A330 rated so I don't know exactly what the crew needed to do to open the door.