how to call non static method into static method

i written this class and when run this class

class Test{

    constructor(p){

        this.fname = p;
    }

    change(n){
        this.fname = n + ' test';
    }

    static show(){
        this.change('iman');
        return  this.fname;
    }

    echo(){    
        return this.fname+' ok';
    }
}

console.log(Test.show());

return below error

TypeError: this.change is not a function