'Here's my special tool' - cost Nil
Two bits of metal, one a bracket off an old washing machine, one, part of a shed hinge, both with an 8mm hole drilled near the end.
For easy of photos - I have removed the fan!
Remove one bolt from the pulley and fit one of the metal parts
Remove another bolt and fit the other metal bar
Bring the parts together and insert another bolt to join both pieces of metal.
Hold tight, insert 36mm spanner or whatever size you need and undo bolt, no need for hitting with screwdrivers, chisels etc.
The P38 one came off easily.
Job done