Hi Tumbleweed, don't know if you have managed this yet but when i took mine off I was having the same orblem, phoned SRM who had done some work for me to refresh my memory and was to told they just use a flat screwdriver and a same piece of wood to avoid contact to the innere case , abit surprised but tried it and it worked, don't go mad on it but a gentle pressure will show if its going to give up the ghost easily or if you need something more refined , best of luck, Bobh.