The Yamaha Grizzly that I have in the shop also has a couple of CV shaft boots that are ripped. This is an important thing to fix as soon as possible. If you operate a vehicle with ripped or torn CV boots the grease can get washed out and dirt can get in, this will quickly wear out an expensive CV joint.
Replacing a CV boot is a simple job. Here are all the parts and pieces laid out on the work bench. The grease in a CV joint is always messy, this is one of the jobs where I wear gloves. I did not take any photos of taking the joint apart (mostly because I was covered in grease), but it is the opposite of putting it together.
First slide the clamp and boot on the shaft.
Slide the next pieces on the shaft. They could be held on with a spring clip or a snap ring like this one. When installing a snap ring take a close look at it before putting it on. One surface has square edges and the other surface will have slightly rounded edges, this is a result of the way that they are manufactured. You should always install them with the square edge in the direction of the thrust.
The next step is to put the balls in place and pack everything with grease. When you buy new boots they normally come with the correct grease to put inside.
This photo shows the clamp being placed on the boot. The clamps come in many different styles. This one is easy to put on, you simply push the end down to tighten it and then bend the tabs over to hold it in place. When installing the clamp you should put it on in the direction that would be less likely for the end to snag on something when it is spinning.
Here is the completed clamp with the tabs bent over. Once you have the joint back together you should check it to make sure that it plunges in and out properly. As the suspension goes up and down the axle length changes and that change is taken up in the CV joint.
Now the axle is ready to be installed in the vehicle.