Method update

/**
 * Generic update method for extensions
 *
 * @return  boolean|integer  The extension ID on success, boolean false on failure
 *
 * @since   3.4
 */
public function update()
{
    // Set the overwrite setting
    $this->parent->setOverwrite(true);
    $this->parent->setUpgrade(true);
    // And make sure the route is set correctly
    $this->setRoute('update');
    // Now jump into the install method to run the update
    return $this->install();
}