After finishing my timing belt, I was looking for the easiest way to torque down the harmonic balancer. I did not want to do it with an impact gun because that's not as precise as a torque wrench. Precise torque is extremely important here to prevent the balancer from shearing off, which would happen if the bolt is too tight, or coming off and stripping the crankshaft keyway, which would happen if the bolt is too loose.
Here is what I came up with:
Step 1: Set the crank pulley at TDC. This is important if you want to be able to put the pulley back on with the marks in the correct position.
Step 2: Remove the pulley.
Step 3: Use one of these universal pulley tools (or make your own) and attach the holes to the balancer with long M6x1.00 screws.
Step 4: Set the torque wrench to 90 ft/lbs and torque away while counteracting the pulley with the special tool.
There, easy as that.