Michael S
It is a regular thread that gets tightened to 150 ft/lbs and tightens up when the engine cranks. You need to hold the crank pulley from turning and use a long breaker bar to get it loose. Very tight, and I just did one.

Shirley
if cam belt is still on,place strong bar and socket on bolt,place end of long bar against suspension or similar,flick starter,magic make sure bar is fitted way or engine rotation

>>--♥♥♥--->
It's regular threaded bolt. See if you can borrow an impact wrench with 1000 + lb of torque to break it loose. If not, use a breaker bar and an a pipe for leverage, but you'll need to buy a harmonic balancer holding tool especially for Toyota. A breaker bar with pipe resting on the car chassis or suspension; and cranking the starter (ignition disabled) is common, but not recommended.

the_boy_toy
It's a regular threaded bolt. If you don't have an impact wrench, you should have an assistant try and hold the flywheel from turning with a screw driver or pry bar. Using a socket and breaker bar, position the breaker so that you can hit it with a hammer. This is the same concept as an impact wrench but much much slower.