Within the foam inserts of your TV's packaging, you will find a small plastic bag that contains a splitter type adapter. One end of this adapter looks similar to a headphone input, with the other end splitting into a yellow/black RCA type fitting.
Please attach this adapter to the 3.5mm coaxial output (CVS/SPDIF) on the rear of your TV. You can then attach your coaxial cable to the black RCA type fitting on the adapter.
Following this, please attach the other end of the coaxial cable to your home theatre/speaker system, and you should then be able to enjoy high quality digital audio.
If you are having issues related to the sound playback, please ensure that any 'SPDIF' settings within your TV's sound menu are set to 'PCM'.
A picture of the cable is shown below: