If you want to accomplish maintenance tasks to your Suzuki GS450 then it will always be recommended to have a Workshop Manual to use as reference just in case you need to know the right way to take off a certain component for example Door and fit it again in the correct manner.
Suzuki GS450 Workshop Manuals provides specified diagnostic details on your car so if something is not working it will help you work out what the problem is and tips on how to correct it. Then you are able to evaluate if you can do this on your own or in case the job is just too big it is possible to make a booking for your GS450 in with a decent repair garage.
Suzuki GS450 manual