My advice to juiceme: if you have troubles with this inside linux, then despite the mental horror, boot into Windows or loan a friend's Windows machine for fifteen minutes. I spent several evenings trying these tools within Linux. Once I swallowed my pride, it was only a matter of 15 minutes until I had successfully downgraded the phone.

At least under Windows 10 I didn't have to download any drivers, just have Mousse04 image on USB stick and download Flashtool. Easy peasy. The DRM backup software seemed to work well within linux after flashing MM.