The crank shaft pulley is held on by a single 22mm bolt. This bolt is torqued to between 177 and 186 Nm, so it can be really tough to get off. Fortunately, besides using a large power bar, there is a sneaky way of getting it off using the power of the engine itself.
To remove the bolt using this method, you'll need a power bar of about 1 meter length, long enough to go from the boltto the ground below the front of the car (angled towards the front).
Once you have the the power bar and a socket onto the nut, you next have to disconnect the crank angle sensor and cam angle sensor from the ECU. There are connectors enabling you to do this at the top of the engine at the pulley side.
Finally, crank the engine over a turn or two until the bolt comes free (it could make a bit of noise when this happens, so be prepared for it).