there is a company called custom konsepts in witney oxfordshire that sell the kits, its not that easy to do, and it put 1 hell of a lot of stress on the doors and where u mount the new mechanism to.
people in america that have done it get fed up the stress it puts on every thing is alot, seeing as u have 1 pivot point, a normall door has 2 hinges so takes the stress. up to u but i have warned u