How is the pulley obstructing the bolt head? I've never done it with a vw engine but the 2 ford engines and one Honda engine I have done it with I just took out the plugs and with a long* something sized, 1/2" drive socket and ratchet I rotated the crank (I had to do this so I knew the engines wouldn't seize up before I needed them)
*as the pulleys stuck out beyond the bolt so I used a long socket to reach.