[jaffazoom]

A rattle gun is your best option, if you don't have one then.....

Done this a few times undoing crank pulley bolts BUT be careful.

Get a breaker bar that is long enough that it will reach the left hand chassis rail when fitted to the socket and installed on the pulley bolt.

Now turn back away from the chassis rail about 12 inches, make sure its secure on the pulley bolt and hit the key to crank the engine ( make sure you disconnect the fuse for the ecu so the engine can't start). the sudden stop on the chassis rail will normally impact the bolt loose.

Use some rags or a piece of rubber so you don't dint the rail.
If it doesn't go the first time turn it back a bit more than the first time to give it a bit more momentum.

This has never failed me but you just have to be real careful