I did see a chap remove the door some years ago when it was new, and it looked like he somehow unclipped it and lifted it off, but I'm not sure-could someone please clarify, many thanks.
Not all ovens have the same hinge mechanism but YouTube has several videos showing how to do this - just look through them until you find your particular hinge style...
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix gas cookers.