^^^^ What red90 says...
on the flywheel housing, remove the drain plug and look up into the hole. when the crank is at TDC, there should be a "slot" in the flywheel that aligns with the drain plug hole.
There's a special part for locking this flywheel slot, but just get another drain plug, drill a hole through the center (a lathe makes it perfectly central) and poke through a 6mm drill bit (turn it around so that the blunt end touches the flywheel, it'll lock in better....you could also push it into place then dab a spot of weld to hold the drill bit into the drain bung, that way you'll have the depth set correctly)
Then on the front of the engine, pull the trangle-ish shaped cover off of the FIP pulley. you should be able to insert a 10mm drill bit in through the hole (careful, as there's several places the drillbit can poke into, making you thinkg it's all ok, but the "proper" hole is about 1.5" deep, so the drillbit will really push in far...that's the one you want.)