| Dead easy. If you have access to a Haynes manual or Duc workshop manual just follow the procedure for changing the OEM rear sprocket.
The only tools you need which you may not have are a 41mm socket for the axle nut and a decent (fairly large) pair of circlip pliers.
You might also want to think about changing your cush drive rubbers while you've got it all in bits.
If it would be of use, I can e-mail you the relevant pages from the workshop manual - just let me know.
Hope that helps,
Neil |