Variable valve inlet sprocket???

[Amicra]

Hi guys. Im in the process of replacing the head gasket on my nissan micra k12 2004 1.0l. i'm just about to remove the camshafts BUUT the haynes manual is telling me before i do this i have to force a minimum of 3 bars air pressure down the oil inlet which leads to the variable valve inlet sprocket. I then have to turn the inlet camshaft anticlockwise until i hear a click (locking pin disengaging). After this i have to turn the inlet camshaft clockwise setting it to the most advanced position. Aparantly if i dont do this when i come to take the sprocket retaining bolt from the inlet camshaft it will damage the locking pin. My first question is, Have any of you guys dont this sort of thing before (remove the camshafts on this engine)and know wether i need to do all this?? or atleast know how important the locking pin is lol incase i **** it.