Its probably to late, but I'll throw my two cents in anyway.

I removed and installed two fan clutches today from an 84 and an 85 300TD (swapped them around).

On one I had to remove the radiator anyway and eventually the waterpump, the other I just did the fan assembly.

I used the open end of a regular Craftsman 10 mm combination wrench with a 2.5 ft cheater pipe on it to loosen the bolts. No PB blaster was needed, no hammering, no problems at all.

Take all four 10mm bolts (going through the water pump pulley) off the foot of the fan clutch, and the fan/fan clutch should come right off (maybe a small tap on the foot of the clutch if its rusted to the pulley. Pop the clips off the top of the fan shroud and lift out the fan and the shroud at the same time.

Loosen the three 17 mm bolts on the back of the alternator bracket, loosen the 13mm alternator belt adjustment bolt, slip the belts off the water pump pulley and the pulley should just come right off with a little tug.