Android Change Navigation Drawer Menu Items Text programmatically

You can change the title of Navigation Menu Item programmatically by adding following lines in MainActivity.java file.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ...
    //other stuff here
    ...
    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);

    // get menu from navigationView
    Menu menu = navigationView.getMenu();

    // find MenuItem you want to change
    MenuItem nav_camara = menu.findItem(R.id.nav_camara);

    // set new title to the MenuItem
    nav_camara.setTitle("NewTitleForCamera");

    // do the same for other MenuItems
    MenuItem nav_gallery = menu.findItem(R.id.nav_gallery);
    nav_gallery.setTitle("NewTitleForGallery");

    // add NavigationItemSelectedListener to check the navigation clicks
    navigationView.setNavigationItemSelectedListener(this);

}

This works fine for me. Hope it'll help you.

Change the code like below in case you rename or remove item from navigation menu drawer list

  NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    if (navigationView != null) {
        Menu menu = navigationView.getMenu();
        menu.findItem(R.id.nav_profile).setTitle("My Account");
        menu.findItem(R.id.nav_mng_task).setTitle("Control Task");
        //menu.findItem(R.id.nav_pkg_manage).setVisible(false);//In case you want to remove menu item
        navigationView.setNavigationItemSelectedListener(this);
    }