Use of the first part will require you to turn PHP on for this template. The action ID will be used in a hidden field in the following form. Alternatively you could hard code the action id in the form below and delete this portion form the template.
<?php
$this->EE =& get_instance();
$action_id = $this->EE->functions->fetch_action_id('Member', 'retrieve_password');
?>
From there the following form can be placed anywhere in your template.
<form id="forgot_password_form" method="post" action="{site_url}">
<div class='hiddenFields'>
<input type="hidden" name="ACT" value="<?php echo $action_id; //or you could hard code this action id ?>" />
<input type="hidden" name="XID" value={XID_HASH} />
<input type="hidden" name="RET" value="-3" /><!-- URL you would like the user to be redirected to -->
<input type="hidden" name="FROM" value="" />
<input type="hidden" name="site_id" value="1" />
</div>
<p>
<label for="email">Email Address</label>
<input type="text" id="email" name="email" />
</p>
<p class="login_submit">
<input type="submit" id="submit" name="submit" value="Submit" />
</p>
</form>