As per your request.
1. Remove rear spoiler (just 4 bolts).
2. Remove left side panel (can find in the Pictorials section).https://www.silverwing600.com/pictorials-how-to-perform-maintenance-f21/left-rear-cover-removal-pictorial-main-fuse-access-t1010.htm
3. Un-plug rear light connector.
4. Install the Perfect Connnector (PC) into the Honda cable.
5. Crimp or solder red lead wire (off of PC) to the flasher units red wire.
6. Crimp or solder the black wire (off the PC) to the flasher units black wire.
7. Crimp or solder the White wire (off the PC) to the flashers units white wire.
8. Secure flasher unit to scooter.
9. Start scooter with left side cover removed,
10. Adjust number of flashes and the duration of the flash.
11. Once happy - reinstal left side cover and spoiler onto scooter.
If your wondering, I manufacture the Perfect Connector. $26.00 plus $1.50 shipping. It makes the job easy and no harm is done to your scooter wiring harness. Some day, if you decide to buy a newer scooter, all you need to do is just unplug the Perfect Connector and replug the stock Honda connectors togeather.