It should tell you in your instruction booklet. On mine I went through the Setup menu and chose Autotune - takes about 5 mins to find all the new channels. In all it found about 10 new channels (most of them the rubbishy quiz ones), apart from Film4 there was a new radio channel. However, I had to manually move them into their numerical order as it had placed them at the bottom of the list. As my husband is absolutely useless with technology it came down to me to do it, but I succeeded! Good luck.