That would be great I know what "wire it into the 9-pin" actualy meant. do I stick the red wire into the 9-pin (where) and the black wire too? (also where). If I remove the panel and find this quartet harness thing (the 4 pin blocks is what I think you mean) is the 12v switched power item clear to find?
That's a fair point sir, the 9 pin is easy find after you pull the L middle cowl. "9 pin" is in reference to the connectors size, they are sometimes called Hitachi connectors.
Here is a link to a popular supplier I, and others, have used.
https://www.cycleterminal.com/110-connectors.html
I don't think there is an easy way to give you switched power with out pulling plastics or installing "equipment". Lets see if we can shed some light.
This article is the color code for the wires.
https://www.st-owners.com/forums/threads/st1300-quartet-harness-pinout.7682/
9-Pin Clear Connector at bike for quartet harness
Harness Side Color ------ Bike Side Color Signal/Function
Red/Green --------------- Red/Green Constant 12V
Light Green/Black ------- Red/Green Switched 12V + ACC 12V
Orange ------------------ Orange Left Turn Signal
Light Blue -------------- Light Blue Right Turn Signal
Red/Black --------------- White/Green Switched 12V
Green ------------------- Green Ground
As SMSW said the accessory harness, AKA Quartet Harness is out of production. I have found them on Ebay more than once. The connection point for the OEM harness is the only unused connector inside the cover, noted with arrow. there are more pictures in this article;
https://www.st-owners.com/forums/threads/st1300-quartet-harness-farkle-wiring-guide.26091/
If previous owner had one installed the easy way to do this is wire taps, if not, the easiest way is wire taps. these are the not known to fail;

The wire size you are working with is 18-24
Going back to the 9 pin, you would connect the black wire from the Quadlock to the Green wire(ground), and the red wire from the Quadlock to the Red/Black wire.
This will be happening on the wires
before the connector, obviously. I had mine wired direct with a connector to the Quartet and my side failed,
@Mellow had a couple of posi taps and we cut out my connector and used Posi taps to go behind the OEM connector. Works like a champ!
I hope this helps.