PLEASE HELP asap 60 POINTS needs to be in Java

A programmer has written a method called replaceLetter that counts the amount of times a letter is present in a word. Your job is to modify this existing method to fulfill a new purpose.

Rather than count the instances of a letter in a String, write a program that replaces all instance of one letter with another. You should directly modify replaceLetter to get this program to work. In the starter code, replaceLetter only has two parameter values. Your new version should have a third parameter to indicate which String value is replacing the existing letter.

For example,

replaceLetter("hello", "l", "y")
returns

"heyyo"
Sample output:

Enter your word:
hello

Enter the letter you want to replace:
l

Enter the replacing letter:
x
hexxo
Hint: The letters will be assigned from the user as String values. Make sure to use String methods to compare them!

import java.util.Scanner;

public class JavaApplication45 {

   public static String replaceLetter(String txt, String txt1, String txt2 ){

       char one = txt1.charAt(0);

       char two = txt2.charAt(0);

       String newTxt = "";

       for (int i = 0; i < txt.length(); i++){

           char c = txt.charAt(i);

           if (c == one){

               newTxt += two;

           }

           else{

               newTxt += c;

           }

       }

       return newTxt;

   }

   public static void main(String[] args) {

       Scanner scan = new Scanner(System.in);

       System.out.println("Enter your word:");

       String word = scan.nextLine();

       System.out.println("Enter the letter you want to replace:");

       String txt1 = scan.next();

       System.out.println("Enter the replacing letter:");

       String txt2 = scan.next();

       System.out.println(replaceLetter(word,txt1,txt2));

   }

}

I hope this helps!