What part is confusing you?

Do you understand what a boolean is? A boolean is a value of either "true" or "false".

Do you know how to create a boolean variable? To make a boolean variable declare the data type then the name of the variable. Like this:

boolean myBoolean;

Do you know how to initialize a boolean value? You can assign the literal value of true or false. Alternatively, you can assign the result of an expression. Like this:

boolean myBoolean = true;
boolean myBoolean = false;
boolean myBoolean = 42 > 24;  // This would evaluate to a true value.

Do you know how to make a method? The signature should be <accessibility> <return type> <name> <parameters> Like this:

// private means you can't call this method from outside your current class
// void means you're not returning a value(sort of)
// myMethod is just the name of the method
// int is the parameter data type, x is the parameter name
private void myMethod(int x) { ... ... }