I don't know why you would want to do that but all you need is the correct load resistor. I don't know what the resistance would be that you need. I do know they make several for putting LEDs on HDs. I use one for my LEDs. You may even need 2 or make your own, any custom bike shop should be able to get you one. Better yet if they had a couple so you could find the correct resistance. It would be like you have a blown rear bulb and then just compensated for it up front. Could even wire it in to the rear signal wires then the flasher would think you still have the rears.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!