How do I hook up a stereo reciver to the technics su-g91

I assume you want to use the SU-G91 as a power amplifier to drive your speakers. If your receiver has connections for inserting an equalizer (may be labeled pre-amp output and power amp input), remove the jumpers between the pre-amp and the power amp, then run cables from the pre-amp to the SU-G91 inputs. You can have an equalizer between the receiver and the integrated amplifier.
If this is not available, use the recording output (for a tape recorder on older receivers). Note that the volume control on the receiver will be bypassed with this connection.