It’s pretty intuitive. There are multiple sizes. Choose the size of your spark plug and use the metal shaft to leverage the wrench to loosen or tighten the plug.
Yes it Will work on most spark plugs that you find on lawn eguipment .
I used it for the Honda plug but I needed a crescent wrench to turn it.
Simply push in opn BOTH of the spring-loaded "balls", which are connected by a "V" shaped spring, then pull the two sections apart. You need to push pretty hard, the V-spring is very strong!
With a little wiggle and effort mine came apart.