I am working on a 2007 Kubota LA1002 tractor and I need to access the controls in the top of the cab. I have no manual. Do I remove the outside top or the interior? If it is the exterior top, where are the bolts that hold it on and if it is the interior, do I need to remove the radio, speakers etc? The compressor is shutting down after 15 minutes of run tme and I suspect one of the switches in the A/C contol unit. Thanks for any info you might have.