The procedure depends on the position of the lever handle to the door hinges.
You will require a 2 mm Allen key.
Proceed as follows for a right-hand lever handle (see diagram below):
To set the end of the lever handle (1) higher turn the grub screw (2)
clockwise.
To set the end of the lever handle (1) lower turn the grub screw (2) anti-
clockwise.
Proceed as follows for a left-handed lever handle:
To set the end of the lever handle (1) higher turn the grub screw (2) anti-
clockwise.
To set the end of the lever handle (1) lower turn the grub screw (2)
clockwise.