Refer to section 8.3.1 Removal of the Rear Case Unit of the Service Manual.

To replace the rear wheel switch, you'll have to split the camera into its front and rear halves. Before you remove any screws, remove the battery and storage card.

Use a small, flat screwdriver to pry out and remove the hot shoe spring. This allows access to screws beneath the hot shoe.

Remove the two black screws as indicated. Leave the silver screws in place.

Remove the following screws around the body of the camera: 2 bottom screws (on rear half), 2 right-side screws, 1 screw on left-hand side.