How to add a simple Custom Field to Address Field

Hi there
Is there any Tutorial that shows me as a non-rocket-engineer how to ad a simple custom field?
i need an field that stores the opening hours in plain text!

What i tried:
A) using the example module
1) I cloned the example folder adressfield/example => myAddressField
to my module directory.
2) renamed addressfield_example.module => myAddressField.module
3) renamed addressfield_example.info => myAddressField.info
4) changed the name in myAddressField.info => myAddress Field

drush cc all

then i tried to find this module in my modules list
admin/modules
to enable it.
but the module did not show up there !?!

B) using a clone from an existing plugin format
1) clones addressfiled/plugins/format/organisation.inc => addressfiled/plugins/format/organisation2.inc
2) changed the code from organisation.inc like following:

/**
 * @file
 * Generates a first name + last name format.
 */

$plugin = array(
  'title' => t('Organisation 2 (single line)'),
  'format callback' => 'addressfield_format_organisation2_generate',
  'type' => 'organisation',
  'weight' => -10,
);

/**
 * Format callback.
 *
 * @see CALLBACK_addressfield_format_callback()
 */
function addressfield_format_organisation2_generate(&$format, $address) {
  $format['organisation2_block'] = array(
    '#type' => 'addressfield_container',
    '#attributes' => array('class' => array('addressfield-container-inline', 'name-block')),
    '#weight' => -50,
    // The addressfield is considered empty without a country, hide all fields
    // until one is selected.
    '#access' => !empty($address['country']),
  );
  $format['organisation2_block']['organisation_name'] = array(
    '#title' => t('Company 2'),
    '#size' => 30,
    '#maxlength' => 255,
    '#attributes' => array(
      'class' => array('organisation2-name'),
      'autocomplete' => 'organization2',
    ),
  );
}

3) drush cc all

4) the field is now available in the field settings and also in the node edit form.
but its not possible to store date!
so, what ic can see now is that my field needs to set up in the function addressfield_field_schema() {}
to be stored.
but where do i have to exand the addressfield_field_schema() ?
in a custom module?
or do i miss something?

very thankfull for any hint!
best regards