I know it's kinda a cheesie way of doing it but it did work for me and, well if it helps.
I'll post pics if I figure out how soon but I just opened it and pulled the LED out and replaced it with the wires from my tail light/turn lights and it's working it's not hard just a battery inside no chip or anything. Then installed as normal.
$2.00
1X Cycling LED Brake Bike Light Tail Rear Bicycle Safety Warning Lamp Waterproof
2PCS, Qty 2
Shipping: $2.00