Gupperino, I used a regulator/rectifier similar to this one. https://www.ebay.com/itm/4-Wires-Voltage-Regulator-Rectifier-ATV-GY6-50-150-Scooter-Moped-JCL-NST-TAOTAO/223707047329?epid=1739699470&hash=item3415faa5a1:g:MHMAAOSwXOVaZuvE
Mine is on a Minarelli V1, similar lighting coil. I detached the lighting coils ground and ran a wire from it out. Some call this floating the ground. Then connected these AC wires to the yellow and pink wires on the regulator. Now you can just use the red and green as your output and even use chassis ground. True it's still a 6-volt coil but I switched to LCD's and there is enough current even at idle to fire the headlight with minimal flicker. A capacitor or even a battery could be added but for keeping it inexpensive and simple this works. Use the search function, there are many here who have done this and similar variations. Go for it!
I left the stoplight circuit alone and simply added an LED tail light. I snuck a diode in just for some cheap insurance. (edited)