Modern "rubber" dies quickly. Something usually hits the boot and starts a tear. Split boots are car lot cobble jobs.. If you get the regular boot, pull the axle, take the inner boot off (big end first, then snap ring so the 3 sided "tripode" comes out carefully so the needles don't fall out. Take the snap ring off the shaft end and tape the needle caps (if they aren't the kind with a clip on the end keeping them together) all the way around to keep them together.
Once the tripode is off, take the inner boot off and tear away the old boot and clean out the outer joint. Slide the new boot down the shaft (if rusty, I use a wire wheel to take most of it off) with a little lube to slide easier.
Probably a youtube showing how to do it