[* black] Insert Spudger between Upper Case and Lower Bezel
[* black] Pry off the Lower Bezel. Some are attached with adhesive to Upper Case, others are glued. Either way, you will break the mini solders and will have to glue (with your own glue) the bezel back when reassembling the mouse.
[* black] Pry off the Lower Bezel attached with adhesive to Upper Case