Start by turning off the mouse and removing the back battery cover and battery of the mouse.

Then remove the teflon "feet" of the mouse to get to the five (5) screws that hold the top and bottom of the parts of the mouse together.

If you want to keep the stickers reusable, consider only peeling back the amount you need to get at the screw. Anymore will increase the risk of the glue sticking to the body of the mouse rendering the sticker feeling bumpy and will cause the mouse to track unevenly.

If you are using brand new stickers, make sure you clean off any excess glue. I found using the glue stuck to the peeled off sticker extremely useful at peeling off the remaining glue.