You need to use a power steering pulley puller (say it three times as fast as you can
) and remove the vacuum pump pulley. Easy peasy after that. I think the bolts are 10mm hex.
If you use a three jaw puller on the outside of the pulley just go ahead and order a new pulley.
Do like me, switch to hydroboost and ditch the mechanical pump for a small electric! I hate those mechanical pumps.