The torque for those bolts is 42 NM (or 31 ft-lbs according to my conversion table). On gas engines (I assume this will also apply to diesel engines although they have twice the compression) you can turn the engine in small increments by using a large headed flat head screwdriver as follows:
1. With the screwdriver shaft against the driver's side of the opening in the bottom of the bell housing, apply the screwdriver blade (parallell to the direction of travel) to the torque converter.
2. With pressure applied to the torque converter, lever the screwdriver towards the driver's side of the car to move the torque converter an inch or so clockwise as viewed from the front of the engine.
3. Repeat until next set of bolt heads appear in inspection window.

Once you have successfully moved the torque converter a few times you will get the hang of the correct positioning of the screwdriver. Also, you can always bump the engine ahead with the starter or a socket applied to the front crankshaft pulley and use this method for final alignment. Mark