Service manual is apparently here over at Elekrotanya: Ignore any big green or red 'bait' buttons on the page and look down at the lower left hand side where you will see the word 'Processing'... for a few tens of seconds.
When that changes to "Download", click on that word to download it. It is a .rar archive file so you will need some sort of UNrar program to un-archive it. I have not done that, so I have no idea what the package contains. Files from Elektrotanya are normally OK.
https://elektrotanya.com/yamaha_clp-.../download.html