Service Manual or replacement part specs for Fantom-S61???

Hi all. I've owned a Fantom-S61 for about 13 years now. I'm starting to have problems with some buttons not working properly and requiring me to press hard or multiple times. It's mainly the frequently used buttons such as the Cursor and Arp/Rhythm. Is there a service manual available for this??? If not, does anyone know the specs on replacement tact switch parts or any guides on how to safely open the unit up? I was able to find a Fantom X-7 service manual, but was not sure if some of the similar parts had the same specs. Thanks in advance. :)