Not sure what to call this whole piece, it's the path the light takes to get there, through a load of lenses.

Undo 4 marked screws - 3x11mm Plastic Tapping

Undo little screw holding an earthing plate near the curved lens - 2x8mm Plastic Tapping Screw

Lift the whole light path up, take note of the focusing slider, you can carefully maneuver it out past it without having to remove it