We have the same style as shown in Oakman's photo - they were almost impossible to open as well. After getting them popped loose with a screwdriver, I used a small file to remove the sharp edges & shorten the tabs a bit in the latches.
We has the other style on our old unit, the type with the little swiveling latches. If it wasn't closed while underway, it would slap in the breeze and make a lot of noise. If we leave this one unlatched, it doesn't seem to make any noise. We may leave it unlatched all the time.
Formerly: 2000 Four Winds 26Q/Ford, '96 Kit Sportsmaster 22' 5th wheel, '91 Sunlite truck camper, Wildernest flip-top canopy