it's not as dangerous as people make it out to be. quite hard to actually do damage during the installation process. as others have said, it's based on the memory card, not the camera. so you can have it on one card but not another so you only have ML when you want it. plus, if you install it, then remove it, and your camera breaks after that, it's still covered since it doesn't change the camera. but if your camera gets messed up while operating ML or while installing it, then idk.
that said, i love ML and have it on all my cards. the white balance feature and mic level feature are my favorites.
i used this video to install it: