When I got back from my walk this morning I took the lounge door off the frame, layed it on some plastic boxes and began to saw a bit off the bottom. I find it quite hard to keep in a straight line but I'm not rushing, fingers crossed I'm not going to wreck it! I would have said where's a man when you need one, but obviously I don't. 

Edit: it's back up now and it's perfect, phew!