I will post my own version of these instructions soon, but in the meantime, here is the Citrix eDocs link for this.
http://support.citrix.com/proddocs/topic/dws-storefront-26/dws-configure-single-fqdn.html#dws-configure-single-fqdn
Xenapp 7.6 - Using a Single URL for internal and external connections. STOREFRONT 2.6
November 14, 2014