Page 8W-30-6 shows the connections of the upstream O2 sensors at the PCM.
C3 pins 6, 7 & 23 and C2 pins 15 & 24.


And page 8W-30-8 shows the connection of the downstream O2 sensors.
C4 pins 5, 15 & 16 and C5 pins 1 & 4.

Not to be snide. But if you cant read the schematics, please dont do any mods to your wiring.... you could mess up you car badly.