I don't seem to keep CV joints in one piece long enough to just tear a boot. I think Andy at nissan4wheelers replaced a boot on his Frontier while it was still IFS. If I recall correctly getting the new boot over the joint was a pain in the ass. Like Carlton said if it still has grease in it and doesn't look too dirty you should be safe with just changing the boot. I bought a set of spare boots from Xterraparts I've never been able to use. Both came with a packet of new grease.