Remove the tire. Remove the brakes. Then you want to remove the Hub axle bearing. The CV just should pull out of the front shaft housing. You can also vist a great site for Grand Cherokee. www.nagca.com. Best thing is to do is go buy the break down manuel for you Grand. find the book for you yr and model and eng. type
additional info: I had a torn CV rubber boot on my 95 GC that had let dirt into the CV joint to the extent that it was making noise and threatening to go out. This is the joint that connects the front drive shaft leading from the transfer case to the front differential and is located right behind the front differential. My local mechanic replaced the CV joint with a U-joint and told me that Jeep has issued a bulletin to do so as the front CV joint was a weak point that caused lots of problems. The good news is that a U-joint is a stronger link and the bearings are permanently sealed so, no zerks to grease and no rubber boots to wear out or rip. The previous answer addressed an issue if your problem was an axle CV joint...mine addressed the issue if your problem is the front drive shaft....you did not specify in your question. Actually your question asked how to replace the shaft which makes little sense as the shaft itself is just a hunk of steel and would never go out unless you also tore up the U-joints, the CV joints and perhaps the transfer case first.