I have a '15 Macbook 12 with OSX Sierra & Bootcamp'd Windows 10. I want to add Ubuntu 17 as a third boot option. I did some Google searching and it seems the only way to do it is by removing Windows completely first. Then starting over with a slightly technical process that sort of tricks the ol' macbook software into compliance. Is there a way to do it with Windows already installed via Bootcamp? AKA nor having to reinstall Windows again. (I hate windows installation) Figured it couldn't hurt to ask. Thanks!