I tried installing it, put the commandbar.htm in the root directory of moi3d, and the customui folder in the root directory like it said above. When I start moi, nothing happens, no new menu items at the bottom, nothing different.

When the instructions say to extract it into the moi folder, does it literally mean into the root moi folder?

UPDATE: never mind, like a dumass I was opening the archive and manually trying to install it, when the directory structure in the archive showed me exactly how it was SUPPOSED to work... facepalm.