You open the little flaps on the inside covers by the spine:
This one I took out the posts and replaced them with another system, but this is where you find the ends of the screws. Open the flap on the front inside cover and back inside cover. Some are really tight to begin with, so you need to hold one steady while unscrewing the other side (I often get my dh to help on new albums when they're really tight). I've even used a pliers to twist one once.