What ever you do DON'T remove the cam pulley or pulleys.(very complicated to reinstall and this isn't needed for the belt replacement.
the cam pulleys have a mark on them the mark looks like a fine slice(groove) find those then turn the engine until they line up with the same marks on the timing cover.
If you check the diagram closely the behind the crank pulley you'll see a smaller wheel that has teeth were the arrow points towards the engine also has a slight groove that groove should line up with the one the block, very fine hard to see, but there use a small flash light. once you line up the cam pulleys the bottom should line up. if you don't see it the first time turn the motor another time line up the top the bottom should be there.