To Klap-in :
I removed it with the Administrator interface in DokuWiki.
The link
https://github.com/splitbrain/dokuwiki/tree/master/lib/plugins/popularity is not a link to a TGZ package as with the others plugins. So, it's impossible to install Popularity plugin like the others plugins.
It would be great to add a link to a TGZ package on this page :
https://www.dokuwiki.org/plugin:popularity , like the other plugins.
To Anika Henke :
Yes, it's true for all the bundle plugins but not for the other plugins. So, why is it possible to delete it and not to add it easily ?