| Red,
You need a special tool to engage into the holes in the headstock nut.
I made one using a couple of 5mm drill shanks set into a block of ally. This fits inside a 32mm socket and that can then be torqued to the correct value (30Nm if I remember correctly).
You then need to back off the nut by 30degrees - use a protractor and a felt tip.
Best thing to do is to strip and re-grease the bearings and then set it up with no weight on the front wheel - a job I'm gonna be doing this weekend. | 
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