Blogdesk-how to enable options-writing.php. Help please?

Hi
Can someone help with this problem please. I'm trying to set up Blog desk to post to my wp blog. I get a message that XML-RPC services are disabled and i need to enable them at wp-admin/options-writing.php.
I've found the above file and have copied below what I think is the relevant bit of code to amend. However, how exactly do I "enable them below"
Thanks for any help.
All the best,
Paul
PS if I can return the favour with some UK tax help let me know.

<h3><?php _e('Remote Publishing') ?></h3>
<p><?php printf(__('To post to WordPress from a desktop blogging client or remote website that uses the Atom Publishing Protocol or one of the XML-RPC publishing interfaces you must enable them below.')) ?></p>
<table class="form-table">
<tr valign="top">
<th scope="row"><?php _e('Atom Publishing Protocol') ?></th>
<td><fieldset><legend class="hidden"><?php _e('Atom Publishing Protocol') ?></legend>
<label for="enable_app">
<input name="enable_app" type="checkbox" id="enable_app" value="1" <?php checked('1', get_option('enable_app')); ?> />
<?php _e('Enable the Atom Publishing Protocol.') ?></label><br />
</fieldset></td>
</tr>
<tr valign="top">
<th scope="row"><?php _e('XML-RPC') ?></th>
<td><fieldset><legend class="hidden"><?php _e('XML-RPC') ?></legend>
<label for="enable_xmlrpc">
<input name="enable_xmlrpc" type="checkbox" id="enable_xmlrpc" value="1" <?php checked('1', get_option('enable_xmlrpc')); ?> />
<?php _e('Enable the WordPress, Movable Type, MetaWeblog and Blogger XML-RPC publishing protocols.') ?></label><br />
</fieldset></td>
</tr>
<?php do_settings_fields('writing', 'remote_publishing'); ?>
</table>