I have a Trevi mixer shower of the type shown in http://www.showerdoc.co.uk/shower-spares/trevi/03.html which is playing up. I can't see how to take it apart. I'm fairly sure I need to remove the front cover plate (item 1 in the referenced drawing), and my strong expectation is that I just lever it off. However, I don't want to scratch up the paint or otherwise spoil its appearance by trying to get it off incorrectly. Can anyone help?