If you choose to accomplish repairs on your own Bimota DB5 R then it is usually recommended to have access to a Workshop Manual to keep just for reference if you want to know tips on how to take off a specific component including Gearbox and match it again effectively.
Bimota DB5 R Workshop Manuals will provide you with distinct diagnostic guides with regards to your car so if something is wrong it can help you identify what the problem is and how you can repair it. You will be able to evaluate if this can be done yourself or if the job is just too big you can make a booking for your DB5 R into a decent car garage.
Bimota DB5 R manual