Originally Posted by S2Dan
When i look mine off i had a mate hold a large spanner against the bottom crank pulley on the other side while i un did the flywheel bolts, bit of a strange way to do it but it worked

The only problem with this method is you end with a mojorly overtightened pulley bolt then....
There is a much smaller tool about which just bolts onto one of the bell housing holes, and has a tooth which locks into the flywheel ring gear.
That other tool looks a right handful to use