Hi mate i did exactly the same as you looking for the timing hole near the starter motor, It is just infront of the drivers side driveshaft where it goes into the gearbox its alot easier if you dissconnect the the plastic turbo pipe that runs under the sump you can then get your hand up easy and insert the pin, i think it was a 6mm drill bit that i used to lock the crank. I used an 8mm drill bit to lock the camshaft, as for the belt tension you should just be able to twist the belt through 90 degrees on its longest run. Make 100% sure after the new belt is fitted that you can insert both timing pins after turning the engine over with a spanner first befor you even attemp to start it off the key. I have the diagram on autodata but it wont let me save it to upload for you. A peugeot 406 haynes manual shows you everthing with photo's as it is the same engine. Hope this helps you.