java - setText on button from another activity android

I have a problem, I want to click on the list, calling a
new activity and rename the button to another name.

I tried
several things, nothing worked, can someone please help
me?

My class
EditarTimes:

private
            AdapterView.OnItemClickListener selecionarTime = new AdapterView.OnItemClickListener()
            {
 public void onItemClick(AdapterView arg0, View arg1, int pos, long id)
            {
 t = times.get(pos);
 CadastroTimes cad = new
            CadastroTimes();

            CadastroTimes.salvar.setText("Alterar");
 Intent
            intent = new Intent(EditarTimes.this, CadastroTimes.class);

            startActivity(intent);
 }
};

public
            class CadastroTimes extends AppCompatActivity {
 private Time t;

            private timeDatabase db;
 private EditText edID;
 private EditText
            edNome;
 public Button salvar;
 @Override
 protected void
            onCreate(Bundle savedInstanceState) {

            super.onCreate(savedInstanceState);

            setContentView(R.layout.activity_cadastro_times);
 edID = (EditText)
            findViewById(R.id.edID);
 edNome = (EditText)
            findViewById(R.id.edNome);
 db = new
            timeDatabase(getApplicationContext());
 salvar = (Button)
            findViewById(R.id.btnCadastrar);
 salvar.setText("Cadastrar");

            String newString;
 if (savedInstanceState == null) {
 Bundle extras
            = getIntent().getExtras();
 if(extras == null) {
 newString=
            null;
 } else {
 newString= extras.getString("Alterar");

            }
 } else {
 newString= (String)
            savedInstanceState.getSerializable("Alterar");
 }
 //button in
            CadastroTimes activity to have that String as text

            System.out.println(newString + "
            AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA");

            salvar.setText(newString);
 }
 public void salvarTime(View v)
            {
 t = new Time();

            t.setNome(edNome.getText().toString());
 if
            (salvar.getText().equals("Alterar")) {
 db.atualizar(t);

            exibirMensagem("Time atualizado com sucesso!");
 } else {

            db.salvar(t);
 exibirMensagem("Time cadastrado com sucesso!");

            }
 Intent intent = new Intent(this, EditarTimes.class);

            startActivity(intent);
 }
 private void limparDados() {

            edID.setText("");
 edNome.setText("");

            edNome.requestFocus();
 }
 private void exibirMensagem(String msg)
            {
 Toast.makeText(getApplicationContext(), msg,
            Toast.LENGTH_LONG).show();

            }
}

public class EditarTimes extends
            AppCompatActivity {
 private Time t;
 private List times;

            private timeDatabase db;
 private ListView lvTimes;

            @Override
 protected void onCreate(Bundle savedInstanceState) {

            super.onCreate(savedInstanceState);

            setContentView(R.layout.activity_editar_times);
 lvTimes = (ListView)
            findViewById(R.id.lvTimes);

            lvTimes.setOnItemClickListener(selecionarTime);

            lvTimes.setOnItemLongClickListener(excluirTime);
 times = new
            ArrayList();
 db = new timeDatabase(getApplicationContext());

            atualizarLista();
 }
 private void excluirTime(final int idTime)
            {
 AlertDialog.Builder builder = new AlertDialog.Builder(this);

            builder.setTitle("Excluir time?")

            .setIcon(android.R.drawable.ic_dialog_alert)
 .setMessage("Deseja excluir esse
            time?")
 .setCancelable(false)

            .setPositiveButton(getString(R.string.sim),
 new
            DialogInterface.OnClickListener() {
 public void onClick(DialogInterface
            dialog, int id) {
 if (db.deletar(idTime)) {

            atualizarLista();
 exibirMensagem(getString(R.string.msgExclusao));

            } else {
 exibirMensagem(getString(R.string.msgFalhaExclusao));

            }
 }
 })

            .setNegativeButton(getString(R.string.nao),
 new
            DialogInterface.OnClickListener() {
 public void onClick(DialogInterface
            dialog, int id) {
 dialog.cancel();
 }
 });

            builder.create();
 builder.show();
 atualizarLista();

            }
 private void atualizarLista() {
 times = db.listAll();

            if (times != null) {
 if (times.size() > 0) {
 TimeListAdapter
            tla = new TimeListAdapter(
 getApplicationContext(), times);

            lvTimes.setAdapter(tla);
 }
 }
 }
 private
            AdapterView.OnItemClickListener selecionarTime = new AdapterView.OnItemClickListener()
            {
 public void onItemClick(AdapterView arg0, View arg1, int pos, long id)
            {
 t = times.get(pos);
 Intent intent = new Intent(EditarTimes.this,
            CadastroTimes.class);
 String strName = "Alterar";

            intent.putExtra("Alterar", strName);
 startActivity(intent);

            //preecherDados(t);
 }
 };
 private
            AdapterView.OnItemLongClickListener excluirTime = new
            AdapterView.OnItemLongClickListener() {
 public boolean
            onItemLongClick(AdapterView arg0, View arg1,
 int pos, long arg3) {

            excluirTime(times.get(pos).getId());
 return true;
 }

            };
 /*private void preecherDados(Time time) {

            edID.setText(String.valueOf(time.getId()));

            edNome.setText(time.getNome());
 }*/
 private void
            exibirMensagem(String msg) {
 Toast.makeText(getApplicationContext(), msg,
            Toast.LENGTH_LONG).show();
 }
 public void telaCadastrar(View view)
            {
 Intent intent = new Intent(this, CadastroTimes.class);

            startActivity(intent);
 }
 public void botaoSair(View view)
            {
 Intent intent = new Intent(this, TelaInicial.class);

            startActivity(intent);
 }
}