If you would like a guide on what to do when changing the cam belt, rather than what not to do, there is a full set on instructions freely available on the MTWC website https://www.mtwc.co.uk/new-5-speeder-page-2/ Look for the "M3W Bulletin Articles" and then click on "Sample Articles". Along with several "how to" guides written by M3W owners there is one relating to cam belt replacement.