The JCE File Browser will replace Joomla Media Field instances of the Joomla Media Manager when the editor is also loaded (such as when creating or editing an article).
It is currently not possible to use it outside of this context.
You could experiment with this yourself by making a change to plugins/system/jce/jce.php, by removing lines 100 - 102, eg:
if ($user->getParam('editor', $config->get('editor')) !== 'jce') {
return true;
}
Please note that any chnage you make will be removed when you update JCE.
This change will not affect the Image button in the Tinymce toolbar.
Ryan Demmer
Lead Developer / CEO / CTO
Just because you're not paranoid doesn't mean everybody isn't out to get you.