Change tag icon (Nepomuk and Dolphin)

[SaverioB]

I tagged some files from Dolphin, creating some new tags from the right sidebar.
When I create a new tag, I can choose an icon to be associated with that tag.

I have two questions:
- is it possible to change this icon at a later time?
- is it possible to remove a tag? Not to untag a file, but to remove a tag from the available tags.

In other words, is there a place where I can edit my Nepomuk tags?

Thanks a lot!
Saverio