This php code gets an item with the same URL title, if one exists then it updates it in expression engine.
<?php
ee()->load->library('api');
ee()->api->instantiate('channel_entries');
ee()->api->instantiate('channel_fields');
ee()->api->instantiate('channel_categories');
$title = 'your title';
$friendlyUrl = 'your friendly url';
$query = ee()->db->get_where('channel_titles', array('url_title' => $friendlyUrl), 1);
if($query->num_rows() > 0)
$row = $query->row();
$entry_id = $row->entry_id;
if ($entry_id != FALSE)
$data = array(
// set your values, see below for an example
'title' => $title
);
ee()->api_channel_fields->setup_entry_settings(1, $data);
if (ee()->api_channel_entries->save_entry($data, 1, $entry_id) === FALSE)
echo 'Error';
else
echo "Success";
?>