Pretty sure there is a teardown on ifixit, but if not, the general thing is
Take off the shiny "feet" at the bottom of the mouse, then take out the screws, it should open freely after that, but there might be a ribbon cable or something between the top half and bottom half so take it apart very slowly and check before prying them apart.
then check the right click for any debris, or stuff stuck in it.
But ill warn you, ive done it to my 2013 mamba tournament edition, and the feet never go back on the same, but maybe its cause i didnt both to change the adhesive.