Delete metadata in WP admin custom columns - wordpress

Question

I want to delete metadata from the admin panel of my custom post in WP. I created my custom column and display the desired metadata inside but when I try to create a button to delete the metadata nothing happens.
My code tries to delete the metadata and user post with foreach.
Any help would be much appreciated.
code Done! 05/05/15:
Change Admin Columns:
add_action( "manage_favor_posts_columns", "change_columns" );
function change_columns( $cols ) {
$cols = array(
'cb' => '<input type="checkbox" />',
'title' => __( 'Título del favor', 'trans' ),
'usuarios_registrados' => __('Usuarios Registrados', 'trans'),
'date' => __( 'Fecha publicación', 'trans' ),
);
return $cols;
}
add_action( "manage_posts_custom_column", "custom_columns_phi", 10, 2 );
Add output metas and delete link in columns:
function custom_columns_phi( $column, $post_id ) {
switch ( $column ) {
case "usuarios_registrados":
$favor_post_meta_datos = get_post_meta ($post_id, 'usuarios_favores');
foreach($favor_post_meta_datos as $term_post){
$user_phi_name = get_userdata ($term_post);
?>
<li><?echo $user_phi_name->first_name;?> | Cancelar</li>
<?
}
break;
}
}
Add init function in admin screen:
function phi_admin_preload_get () {
if ( isset($_GET['value_phi_user'] )) {
$phi_get_post = $_GET['value_phi_post'];
$phi_get_user = $_GET['value_phi_user'];
delete_post_meta ($phi_get_post, 'usuarios_favores', $phi_get_user);
delete_user_meta ($phi_get_user, 'favores', $phi_get_post );
}
}
add_action ('admin_init', 'phi_admin_preload_get');

Answer 1

Done!
Change Admin Columns:
add_action( "manage_favor_posts_columns", "change_columns" );
function change_columns( $cols ) {
$cols = array(
'cb' => '<input type="checkbox" />',
'title' => __( 'Título del favor', 'trans' ),
'usuarios_registrados' => __('Usuarios Registrados', 'trans'),
'date' => __( 'Fecha publicación', 'trans' ),
);
return $cols;
}
add_action( "manage_posts_custom_column", "custom_columns_phi", 10, 2 );
Add output metas and delete link in columns:
function custom_columns_phi( $column, $post_id ) {
switch ( $column ) {
case "usuarios_registrados":
$favor_post_meta_datos = get_post_meta ($post_id, 'usuarios_favores');
foreach($favor_post_meta_datos as $term_post){
$user_phi_name = get_userdata ($term_post);
?>
<li><?echo $user_phi_name->first_name;?> | Cancelar</li>
<?
}
break;
}
}
Add init function in admin screen:
function phi_admin_preload_get () {
if ( isset($_GET['value_phi_user'] )) {
$phi_get_post = $_GET['value_phi_post'];
$phi_get_user = $_GET['value_phi_user'];
delete_post_meta ($phi_get_post, 'usuarios_favores', $phi_get_user);
delete_user_meta ($phi_get_user, 'favores', $phi_get_post );
}
}
add_action ('admin_init', 'phi_admin_preload_get');