How do I remove a toilet cistern flush valve (and cradle)?

There were some very helpful answers here on fixing a flush unit (see http://www.howtomendit.com/answers.php?id=81205). I now want to buy a new flush valve (Dal 5443492) to replace the one in my cistern. However, in order to get at the valve itself and take it out, first I need to remove the cradle (Dal 31.05.12) which holds the bellows. How is this cradle removed? (Cradle and flush valve are pictured here: http://www.lunns.net/cisternspares). Should it just 'snap' in and out of position? I've tried trying to pop the cradle out but it looks fairly fragile and I don't want to force it. (There is some flexibility in the cistern 'wall'). Also, does the valve itself just then screw out for easy replacement with the new one? Many thanks for any advice.