I misstated that LED's have low resistance, I meant to say they have low current flow. The lighting control module does not have a separately replaceable flasher. It is already an electronic flasher, but it is designed to work with a certain amount of load (the original bulbs).
I don't know of any way to modify the LCM to work with LED bulbs, but if you found some electrical engineering guru who could reverse engineer and modify the circuitry, maybe you could do it.
Otherwise you would have to completely bypass the LCM, and that would require a good bit of rewiring.
Here are some diagrams to show the stock setup:
To get the no-load flasher installed, you would have to cut the two wires in this diagram labeled flasher power input and flasher output, and connect them to the aftermarket no-load flasher instead. Then you would have a third ground wire on your aftermarket flasher to connect to ground somewhere under the dash or add it to a pre-existing ground point. Make sure to tape off the cut ends so they don't short out and damage your LCM. I don't know how the LCM will respond to this modification, you may get codes as a result. There could be unexpected results. But it should work the LED's.
The LCM is located under the dash, to the right of the steering column. It has three connectors on it.
Here is a page with a lot of info about Ford LCM's:http://www.p71interceptor.com/lcm/