How do I convert from 3-way switches to dimmers?
Since the existing install is using black wires as grounded (neutral) conductors, you should start by rewiring the original circuit to be code compliant.



Then you'll wire the new dimmers in like this.



With the dimmers installed, you'll have something like this.



You'll notice that T2, that runs from F to DD is not labeled. This is because I'm not sure which wire it is in your photos.