You should find that there is a tiny gap between where the screw came out and the screen itself. Just gently insert a pointy object in that gap to give you a bit of leverage and then wiggle the screen out. The screen is inserted into the plastic group head seal, so you need to be gentle but firm with it. I pull the seal and both shower screen and dispersion screen out every few months to give everything a good clean. It can feel a bit tight and frictiony, but it does come out.