Need help removing window treatment for blind repair

I think DH took out the screws on one side to see if there was any give to it and it was still firmly stuck.

(We're considering replacing ALL of the blinds in the RV with simple pull down privacy blinds, since we find we never use the day shades anyway. The tinting in the windows cuts the incoming light sufficiently for our needs. But we're looking for the simplest thing first.).