Deactivate and DElete WPMU Dev

I installed Smush Pro yesterday to play with it. Now, I have WPMU Dev in my dashboard and don’t want to use it. I am unable to deactivate it in plug-ins. I’ve deactivated SmushPro. This is very annoying……I just want to get rid of it and have spent a couple hours today attempting to do so.

When I click on deactivate, it opens a window to a plugin I want, “buy me a cup of coffee”. I’ve tried it on different browsers. Short of taking a hammer to it, I’m at my wits end! Help! How can I remove this completely from my wordpress site?!