Honda offers paper-only versions of factory shop manuals. Any digital copy you find is a pirated version, and it likely not to be the correct one for your specific mower. Honda sells their genuine paper shop manuals on eBay (free shipping and updates for three years); here's a link to exact manual for your HR215HMA.
Honda HR215 Shop Manual
Is the blade clutch not working, or the drive clutch not working? Got a serial number off the back of the mower deck? I can share a few pages of troubleshooting tips if you'll share that number...