Foot-Mouse

You need Logitech G305 internals to fit this. It's a simple transfer, no soldering required, only a screwdriver required. The wires inside the G305 are very delicate, getting them out without any damage might be a little tricky.

You should probably print the top shell sideways, so that the buttons have the most durability. I recommend low infill (10-15%) and 3 shells. The amount of shells and infill will change how hard the buttons are to press down.

The battery goes in before you screw it together, so for replacing it, you have to unscrew the base 4 screws. You may want to tape the battery down if you're prone to smashing the mouse around. It's going to stay in place with normal usage, but it could pop out in theory.

You'll also want to add some mouse feet, because the screws can protrude a little bit from the base and may scratch your floor otherwise.

I've personally used this for browsing the web (mildly annoying without a scroll wheel, but still