Hello Tabitha, was just wondering why noone replied to you after a long while. You could probably learn a lot from above posts. more than I can tell you. I know more about the front axles than anything.

 

I've done it on a 550, if the 660 is similar, you remove the back wheel, take the nut off the centre of the hub, remove the brake calliper, lave it connected to the pipe and hang up so the pipe isn't stretched or kinked. Remove the disc, then the two long bolts from the top and bottom wishbones. Slide the assembly off the driveshaft. Replace the disc and centre nut about four turns and give the disc a sharp pull which should result in the driveshaft assembly popping out of the diff. I suspect those who have fitted O rings etc, may have trouble getting it out. Once the assembly is off, the clips can be removed from the inner CV boot, and the boot slid down the shaft. Dirty job warning, everything is covered in slimy grease. Keep dirt out while removing the snap ring just inside the assembly, ***** have a habit of dropping out when you slide the inner part of the CV out of the outer. Remove the circlip on the end of the shaft and slide the inner CV off the driveshaft. Generic videos of how to fit new CV boots will show most of this.

 

Hope everyone was able to get things addressed without having to replace parts - as axles can cost a pretty penny from the manufacturer. (If you end up having to replace, though, take a look at these guys - decent prices, good support as well.