Removal and / or replacement of the Duŝo standard 8 litre per minute flow regulator for a higher rated flow regulator.
Remove the spray plate using the hex key and multi-tool. Hold a plastic container beneath the shower head then actuate the flow to force the flow regulator out of its recess. Replace the flow regulator and circlip, making sure that the internal 'active' o-ring is facing upstream. Replace the spray plate and screw into place.