No L clips on these the valance is in pretty solid. Thought the screws for curtain track maybe long into wood framing but thats not the case removed them and mounting for map light also.
To tear this out can cause damage to ceiling and cabinets.
You can try and pry strips stapled on valance may have screws in back.
I would call Newmar with your coach number and ask how these two units are mounted and what are holding them up.
Have you tried cleaning the fabric or are you just looking for a change.