Hi again, Henry
The Post Office lost the right to supply TV licences because their bid wasn't as competitive as that of PayPoint.
Your friend should simply go to his nearest store which offers the PayPoint service. Many Co-op grocery stores can accept PayPoint payments, as can lots of newsagents.
To find his nearest PayPoint, follow the links from here:
http://www.tvlicensing.co.uk/waystopay/paypoin toutlet.jsp
(For alternative methods of payment, see the links down the left of that page).
Chris