When you remove the pulley, the cam will most likely 'jump' back slightly. This is absolutely fine, when you refit the pulley, just turn the bolt until it's tight and starts to turn the cam and then pin it up again and loosen the bolt to gain pulley free play again.
Please don't take offence to this Mike, but from what I've been reading, you really shouldn't be undertaking this job as it sounds like you are very unsure and this isn't an engine you can be unsure about when it comes to cambelts.
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"Supercharged - 454.1bhp/317.5lb/ft"Peugeot 306 GTi-6
2000 (X), Moonstone