1. Select any non-privete torrent.
2. Open Trackers page in the bottom.
3. Select any tracker from list.

There is no way to edit this tracker, only replace available. But what if I want to edit already exist tracker instead of replacing it with another? I want to change few letters but can't do this.

Also here is problem with private torrents. I can disable some trackers in the list but have no ability to remove them completely. When I select enabled tracker "Change tracker" button become enabled too. Actually I can't change tracker but why this button become enabled?