MD5 Password login is not working laravel 5

I want to change my password field bcrypt to md5. In database i am storing password in md5 but login is not working

myController:

 public function postLogin(Request $request)
 {
   $this->validate($request, array('username' => 'required', 'password' => 'required'));
$credentials = $request->only('email', 'password');

if (Auth::validate($credentials)) 
{
    $user = Auth::getLastAttempted();
    Auth::login($user, $request->has('remember'));
    return redirect()->intended($this->redirectPath());
}
return redirect($this->loginPath())
->withInput($request->only('email', 'remember'))
->withErrors([
    'email' => $this->getFailedLoginMessage(),
]);

}

via Chebli Mohamed