Changing instance of a class from another class - class

Question

I am trying to use 1 class to change the values of another class.
My first class is Employees. My second class is address.
public class Employee {
private String name;
private Address address;
constructors:
public Employee(){
address = new Address();
name = "";
}
public Employee(String name){
this.name = name;
this.address = new Address();
}
public String getAddress(){
return address.getAddress();
}
public void changeAddress(String number, String street, String city, String province, String postalCode){
address.setNumber(number);
address.setStreet(street);
address.setCity(city);
address.setProvince(province);
address.setPostalCode(postalCode);
}
In my Address class I have a constructor and setters.
When I'm testing,
public static void main(String[] args){
Employee s1 = new Employee("John Doe");
s1.changeAddress("0141", "No5 Road", "Seattle", "WA", "65897");
This doesn't work, because I didn't create an address class.
so that made me try:
Address a1 = new Address();
but how do I link the new address and the employee class together?
I'm not even sure if I am supposed to manually create an address class using Address a1 = new Address() in my tester; or if I am able to include this in my Employee class so I am able to call the changeAddress method without typing out the new address class every time.
The change address method is in the employee class. The address class only has a constructor and setters.