Changing from JavaBeans to Builder pattern

I am using Retrofit in my app, I have the POJO classes that I use to make the request and parse the response. Currently I am using JavaBeans pattern and have getters and setters for all the variables in the class for all POJO classes.

Here is my user class for instance

public class User {
@SerializedName("user_name")
private String userName;
@SerializedName("password")
private String userPassword;
@SerializedName("address_info")
private AddressInfo AddressInfo;
@SerializedName("contact_info")
private ContactInfo ContactInfo;



 /* 
   *@return The userName
 */
public String getUserName() {
    return userName;
}

/**
 * @param userName The userName
 */

public void setUserName(String userName) {
    this.userName = userName;
}

/**
 * @return The userPassword
 */

public String getPassword() {
    return userPassword;
}

/**
 * @param userPassword The userPassword
 */

public void setPassword(String userPassword) {
    this.userPassword = userPassword;
}

 /// so on for the AddressInfo and ContactInfo

}

This works well.I am trying to make use of builder pattern instead of the JavaBeans pattern.

I changed my User class to :

public class User {
@SerializedName("user_name")
private String userName;
@SerializedName("password")
private String userPassword;
@SerializedName("address_info")
private AddressInfo AddressInfo;
@SerializedName("contact_info")
private ContactInfo ContactInfo;


 public static class UserBuilder {

    private String userName;
    private String userPassword;
    private AddressInfo AddressInfo;
    private ContactInfo ContactInfo;

   //builder methods for setting property
    public UserBuilder userName(String user_name) {
        this.userName = user_name;
        return this;
    }

    public UserBuilder userPassword(String user_password) {
        this.userPassword = user_password;
        return this;
    }
   public UserBuilder AddressInfo(AddressInfo addressInfo) {
        this.AddressInfo = addressInfo;
        return this;
    }

    public UserBuilder ContactInfo(ContactInfo contactInfo) {
        this.ContactInfo = contactInfo;
        return this;
    }

     //return fully build object
    public User build() {
        return new User(this);
    }


}

//private constructor to enforce object creation through builder

private User(UserBuilder builder) {
    this.userName = builder.userName;
    this.userPassword = builder.userPassword;
    this.AddressInfo = builder.AddressInfo;
    this.ContactInfo = builder.ContactInfo;
}

//Getters for userName,userPassword,AddressInfo and ContactInfo

AddressInfo class

public class AddressInfo {
@SerializedName("address_1")
private String address1;
@SerializedName("city")
private String city;
@SerializedName("state")
private String state;
@SerializedName("zip_code")
private String zipCode;

 /**
 * @return The address1
 */
public String getAddress1() {
    return address1;
}

/**
 * @return The city
 */
public String getCity() {
    return city;
}

/**
 * @return The state
 */
public String getState() {
    return state;
}

/**
 * @return The zip code
 */
public String getZipCode() {
    return zipCode;
}


 }

Question: 1. I removed setters from AddressInfo and ContactInfo POJO classes. Do I need to implement the builder pattern in AddressInfo and ContactInfo classes as well? Is that how the pattern works.

2. 
   

   How can I achieve this:

   
   

   
     User user = new User.UserBuilder().userName("test").userPassword("******").address("100 Townsend St").city("San Francisco").zip("94107").build();