What engine do you have? The 4 bolts probably only hold the pulley on, there should be a large nut that is what holds the fan clutch on. There is a fan clutch tool and most parts stores will rent this so you can remove it, check it is may have reverse threads. Once I know what engine I can answer this much better.

Oh yea standard or grand cherokee?

Its a straight 6. 4.0L

Looking at the fan clutch for that engine it should only be the 4 bolts that hold the clutch to the water pump. Once that its off then there are 4 bolts that hold the fan to the clutch.