I would leave the center bolt in, just remove the three holding the fan onto the fan hub. Don't remove the four bolts around the perimeter of the fan.
Once the three bolts near the middle are out (they may be "triple square" bolts that you need the CV Joint tool to remove), just grab the front of the fan where the alternator belt runs, and wiggle it. There is a dowel pin between the fan hub and the fan, and that can help the fan to stick on the hub. Wiggling it for a while will help break that bond and it will come off.
Do you have a Haynes manual? If not, get one. It's usually less than $20, and has about 85% of the actual pictures and words from the factory book. It's not a great manual frankly, but it's about as good as we have. Tom Wilson's book on aircooled VW engines is also worth having if you're going to tear the engine down yourself.
Here's a link to a Pelican page with an exploded diagram from the factory manuals (also replicated in Haynes) :
http://www.pelicanparts.com/914/parts/engi...oling_large.htmIn that pic, the fan is #11, and the pulley part of the fan is #12; they are held together by four bolts. The pulley part makes a good handle, so don't remove those bolts if you haven't already. The three bolts that hold the fan onto the hub are #6 (two are not shown). The hub itself and the central bolt holding it onto the crankshaft are not shown in this picture either, but it gives you a reasonable idea what the parts look like.
--DD