hard to give you a good answer.if the gearing has fallen to bits in locked position then will be extremely difficult to release. you have to consider a number of things.do you have a replacement locking mechanism;is it the correct one (there are many).if you break the frame or sash can you secure your property.if you do want to give it a go then remove the glass unit first.i do not recomend that you do!!!
if you call someone out remember they will charge you!
weigh this up against the cost of a new door.remember the security of your home
levi lewy
July 2008