Ok, I decided if I want to do a proper job then it is best removing the panel to measure it properly.
I have removed the beading but the existing panel sits behind the door frame so will not just pop out. It looks like to get the panel out it is necessary to dismantle the frame :shock...
I am replacing the bottom panel on my rear upvc door and obviously need to find out what size it is before ordering the new one. Is there a way of determining the size without taking the thing out?
Cheers
Dave