This is sorely lacking. After taking out the thirteen screws on the top plate, there is a hidden screw under an inconspicuous sticker (that's textured to look just like plain black plastic) facing the USB type-C port. Peel that sticker to reveal the screw and unscrew it before attempting to lift the top plate off.

do you think it is possible to take the the glass-and-sensor part from a black/space grey Magic Mouse 2 and attach it onto a Magic Mouse 1? (I know it sounds weird but I like the color of the 2 and the fact that the 1 is AA-powered

Is it possible to take the black glass top from a 2nd gen magic mouse and put it on a 1st gen magic mouse? I prefer the AA battery setup of the 1st gen, but I’d love a black version