the best way to increase mechanical advantage of the following second class lever is
One way to increase the mechanical advantage of a second-class lever is by increasing the length of the lever arm (the distance between the fulcrum and the point of application of force). By increasing the length of the lever arm, more torque can be produced for a given applied force.
Additionally, increasing the load arm (the distance between the fulcrum and the load) while keeping the effort arm (the distance between the fulcrum and the point of application of force) constant can also increase mechanical advantage.
It's important to note that the mechanical advantage of a second-class lever is already inherently greater than a first-class or third-class lever, since the load is located between the fulcrum and the point of application of force.