K3 - 3 Bladed unit:

• Lock the unit in gear if possible - not critical

• Loosen both of the two M8 set screws - white arrows - until their outer ends are just flush with the boss. Very early models  - circa 2004 - with a bronze boss may only have one M8 set screw for locking

• Undo the M8 Cap Screw - blue arrow  - Very early models will not have this back up screw

• Undo the square drive nut - red arrow - with a 1/2" square drive socket set with no socket mounted - Anticlockwise

K4 - 4 Bladed unit:

• Lock the unit in gear if possible - not critical

• Undo the M8 Cap Screw in the centre of the square drive nut - Blue arrow - Anticlockwise

• Locate the spigot pin protruduing into the internal recess of the nut that locks the nut - 1 of 8 possible places  - White arrow indicates 1 / 8 possible locations

• Undo the M10  set screw set with the spigot attached  - Anticlockwise -  and withdraw the locking spigot

• Now undo the square drive nut - Red arrow - with a 1/2" square drive socket set with no socket mounted - Anticlockwise