A Clymer manual will show you how to do any repair on the bike. Realize that a new shift drum will be very expensive. Even gasket sets for Japanese bikes are outrageously overpriced.
Check bikebandit.com for the parts blowup on the shiftdrum to see if there are subassemblies you can replace. You can also try to find a shift drum at a bike salvage yard.
Changing the shiftdrum requires pulling the engine and completely dismantling it. That will take a lot of hours if you've never done a motorcycle engine before. It'll take a lot of hours if you have done a motorcycle engine before. Since it's a Honda it may also require some special tools.... Honda loves that. The difficulties of rebuilds and the outrageous cost of parts explains why Japanese bikes are throwaways.
Check bikebandit.com for the parts blowup on the shiftdrum to see if there are subassemblies you can replace. You can also try to find a shift drum at a bike salvage yard.
Changing the shiftdrum requires pulling the engine and completely dismantling it. That will take a lot of hours if you've never done a motorcycle engine before. It'll take a lot of hours if you have done a motorcycle engine before. Since it's a Honda it may also require some special tools.... Honda loves that. The difficulties of rebuilds and the outrageous cost of parts explains why Japanese bikes are throwaways.