Do it on both sides, and it should allow you to remove the drawer. Use a flathead screwdriver to lift the lip out of the slider. You’ll be able to see the white lip on the bottom side of the drawer, near the front. To remove the drawers, first, you need to remove the plastic lips.

The drawers aren’t held on the sliders with screws but rather a small white plastic lip that fits inside the slider. I saved IKEA Rationell for last, as this one is the trickiest I’ve encountered when it comes to drawer removal.