Connect with componet cables.
The only digital audio input for this TV will be via the HDMI input. Of course, even with HDMI in, you're only going to get a simple stereo output from the TV. You can use the analog L & R audio inputs for a very similar sound from the TV speakers.
The digital multi-channel audio (Dolby Digital, THX, 5.1, 7.1, etc) encoded in the program should be connected to a suitable multi-channel amplifier with either a TOSLINK (optical), RF (coaxial) or HDMI cable for theatre-like sound. This can be done by (a) cabling from the source (DVD, BluRay Disk, Set Top TV Tuner, etc.) directly to a multi-channel amp and speakers, or (b) from the HDMI output of these devices (DVD, BluRay Disk, Set Top TV Tuner, etc.) into one or both of the TV's HDMI inputs. This will provide only stereo sound output from the TV speakers. You should connect the TV's TOSLINK optical "Digital Output" jack with an optical cable to the amplifier's TOSLINK optical input jack to obtain theatre sound.
To listen to the program shown, you would select the amplifier input assciated with the optical, RF or HDMI input that is connected to the source (DVD, BluRay Disk, Set Top TV Tuner, etc.) if connected directly. If the TV HDMI input(s) are used, they are output to the TV optical output and should be connected to the amplifier optical input. The amp input associated with the optical input should be selected to hear the program with theatre-like sound.