you will need to remove the crank pulley. The bolt has REVERSE THREAD!!! you will need to remove the transmission flywheel cover and use a screwdriver or other suitable object in the teeth of the flywheel agains the bellhousing of the trans to hold the crankshaft whil you break the bolt loose. The pulley and bolt will come off as one piece. The bolt does not come out of the center of the pulley.
that should allow you sufficient clearance to extract that darn alternator!! If this helps, please accept my answer!!
Good luck and thanks for using just answer!