Go to the settings page > Add-ons > My add-ons
Then whichever category your add-on is in (video add-ons probably in this case), highlight the add-on then open the context menu (long-press on the screen, or press C or right-click if you have keyboard or mouse available) and select Add-on information. From there select Uninstall.
Note that assistance with removing them is the only support that we offer for
banned add-ons (wiki), which I suspect the one in your title would come under. You may want to read the notes on
free content (wiki) before continuing too far, and be far more selective about what you install.
This blog may also be enlightening reading as well.