Here you see the top panel of the Kurzweil PC88 turned upside down.

To remove the circuit board holding the bad tactile switches, you must first remove the jacks chassis.

Remove about 10 black screws from the rear-panel, most of which are identified in these photos.

Set the top panel on blocks, as seen here, so when you reinstall the circuit board the buttons can fall through the panel cutouts.

With the rear screws removed, swing the jacks chassis away from the panel.  You can leave all the cables attached.

Two foil sheets are used to shield the panel circuit board.

The screws that fasten the shields also fasten the board.

Remove all the screws holding down the white shield.

Remove all the screws holding down the silver shield.

Under the silver shield you'll see two circuit boards.

The small circuit board holds the Assignable Slider controls.

To keep the small board from falling out, temporarily reinstall two of its mounting screws (right).