Chubbs website at http://www.chubbs.co.uk/ has some very useful service documents available online. You need to click on the the up/down arrows on the right side of the SH101 button. The the menu item Service Manual appears and then click the up/down arrows next to that and you will get a list of the documents available. At first I couldn't find it but then after some clicking around I found how to navigate the site.