Java char array add and change words

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Java

code that prints the scanned word, would want the program to print word where any occurrence of z is replaced with y

public class Char {

    public static void main(String[] args) {
        System.out.println("Please enter your words");
        Scanner scan = new Scanner(System.in);

        String word = scan.nextLine();

        for(char a : word.toCharArray())
        {            
            System.out.println(a);           
        }
    }
}

What I have tried:

changed code several times with different arguments