Margaret, this is not too easy as you have to get the trim off from the underside - this is fitted with clips that are "one way" i.e. have barbs which make them easy to push on but hard to pull off - at least the mini heki has, and the trim looks the same.
If you search the forum topics Technical and Equipment there were some posts around the end of last year on the subject, but I recall that the writes said it was none too easy, although actually harder to describe than to do.
hopefully someone who has done one will read this and reply.