I have spec D headlights for months I've put up with that AFC flashing. Now it's starting to annoy me. How do I disable it from flashing?

 

I assume you are referring to the AFS light not AFC? You cant actually disable it unless you remove the AFS fuse completely but that will mean you loose auto headlamp levelling too. I just opened up the cluster and blocked that light completely so you cannot see it at all.

 

He did mention that he installed aftermarket light which is already lost AFS function.
As for disable the AFS, just pull the fuse and you are good