How to update various WPMU plugins

I have been trying for weeks now in an effort as self help to update the WPMU plugins, Snapshot, Slide-in and WPMU Dashboard. Each time I click on "Update" it just takes me to an identical page which in turn takes me to the same identical page which in turn tales me to the same identical page. I hope you get the idea. So how the hell do you update these or in the future other WPMU plugins?

Aso where is the WPMU Dashboard? I see nothing different than the default WordPress admin pages.