1. unclip the fan shroud, hang over the fan.
2. secure the fan pulley from behind using a piece of 1/4" steel rod, bend at a 90 degree angle 1/4" from the end.
3. remove the fan using a 8mm allen socket, or use an 8mm allen wrench with a 12mm deep socket on a breaker bar.
4. Loosen the big 19mm bolt clamping the front of the belt tensioner, at least one full turn.
5. Loosen the 13mm adjusting nut on the top of the belt tensioner until the tensioner is slack.
6. Remove belt.
7. Reset the indicator pointer on the front of the tensioner to the bottom of the ramp cast onto the tensioner.
8. Tighten the adjusting nut until the pointer is at the top of the ramp.
9. Tighten the 19mm bolt (75 Nm).
10. Reinstall the fan (45 Nm on the 8mm allen bolt), remembering to slip the fan shroud back over the fan before installing the fan, remove the fan pulley holding rod.
11. Install the fan shroud.