If you have to undertake adjustments to your Highland 450 MX then it is usually a good idea to have access to a Workshop Manual for a reference in the event you want to know the best way to remove a certain part including Door and install it again efficiently.
Highland 450 MX Workshop Manuals are able to offer specific diagnostic information for your vehicle therefore if something is broken it will help you find out what the issue is and methods to fix it. After that you can decide if this can be achieved yourself or that the job is simply too big you can book your 450 MX right into a nearby friendly mechanic.
Highland 450 MX manual