I guess i misunderstood you in the beginning.
Those lines are presented in one of the
Custom HTML module (not in any PHP file)
Through Joomla Module Managers, find this module:
Bottom-A (right)
Attachment ScreenShot2015-01-13at9.13.48PM.png not found
Click the HTML icon to see the HTML lines in this module. You will see these lines:
<div class="floatleft width50 facebookLike">
<div class="fb-like" data-href="http://www.facebook.com/flexibleWD" data-send="false" data-width="200" data-show-faces="false" data-colorscheme="dark"> </div>
</div>
<div class="floatleft width50 NewsletterBox" style="text-align: right;"><form id="newsletterform" action="#" method="get" name="newsletterform"><input class="newsletterinput" onfocus="if(this.value=='Sign up for e-mails') this.value='';" onblur="if(this.value=='') this.value='Sign up for e-mails';" type="text" name="email" value="Sign up for e-mails" size="20" alt="Sign up for e-mails" /><input class="newslettersubmit" type="image" alt="" /></form><span class="newsletterdiscounttext"> Get 15% off your next purchase </span></div>
from there, you can change the
data-href="www.facebook.com/flexibleWD" to your Facebook fun page's URL.
Regards.