there should be a hole by the gearbox half way up on the block going towards the the gear box that is a locking point for the crank on the cam it should be on the cam gear with out looking at the timing book at work i recon it should be about 10 past ont the cam put a bolt through there and a drill bit for the crank. You can replace it with out taking the engine out time wise i think its about two maybe three hours the hard part will be cracking the crank pully but if you have a half inch bar and a 22mm socket i think you can do it using the starter motor if you need any more info pm me