I never figured that one out myself. it seemed every time that I wanted to hear a certain artist, there came with it a new station. sorry, i don’t think that it is possible.

Under the Your stations menu, next to each station you will see a little down arrow. If you click on the arrow, a menu appears and at the bottom it allows you to delete the station, assuming it isn’t one of the “shared stations”, in which case you can’t delete it but you can remove it from your list. Try that.