LEDs For Headlights

I am sure this has been covered before, but can someone direct me to a thread or explain to me a way to mount a LED for use as a headlight? I am thinking specifically of Athearn and Stewart F units and Athearn GPs and SDs. I’ve seen Joe Fugate’s new video on mounting bulbs in his Geeps, but how do you do this with LEDs? …and, how do you fill the headlight opening with the LED or bulb? Since I am in the process of installing decoders in my loco’s, I thought I might as well upgrade the lighting as well. Comments, ideas, and especially pictures would be most welcome. Thanks to all.

Mike

LED’s need approx. 3 volt regulator and a resistor (600 ohm?) - in short a package - to run off track power, and requires 5 V. to illuminate.

1 1/4 v. bulb’s only need a bridge rectifier and a 12V ballast (such as the motor to do same), and also need’s 5V .if directional diodes are used.

A 12V (or 14V) bulb can be connected directly, but will require 8 +V. to acieve satifactory brightness.