Try to search next time.
Stiffer clutch springs will make your engine rev higher before the clutch engages, thus when you take off you will actually take off and not just putt-putt away. It's a mod that is solely for low end gains. If you search you will see that you need to tighten up the springs when you get it.
You'll need to have a clutch puller and piston stop to get your stock clutch off. Also the 3-shoe clutches aren't notched for the woodruff key, so you gotta put it on with an impact wrench. Also, if you ever want to take it off (which you will) you have to tap threads into holes.
If you've got to ask, it might just be a lot easier to buy the stiffer springs and put them into your stock 2-shoe.