This step is fairly straight-forward. Remove the screw, then gently lift both catches and pull to the right.

The ink cartridges are held in place with a catch at the top (picture 2). You can release the catch with your finger.

I'm not sure if this is universal, but my ink cartridges come with plastic sheets attached to them (picture 3). I just pulled the sheet (gently) and the ink cartridge slides out.