Can I change the license on a work after I publish it?

Creative Commons licenses are irrevocable for as long as the underlying copyright lasts. Practically that means: once you've licensed a copy of the work under, say, CC BY 4.0, every person who has obtained that copy can rely on those terms forever.

You can absolutely re-license a future copy under different (more permissive or more restrictive) terms, or stop distributing the work entirely. But you cannot pull back permissions from copies already shared.

Update the catalog entry if you change the license on the source — the catalog should always reflect the current license at the source URL.