How do we change from unitary to federal?

Part 1 of 3

There are no clearer marching orders given to Congress than the pronouncement of President Rodrigo Duterte in his recent SONA that the Philippines should adopt a federal-parliamentary government modeled after France, with a “strong” President. Federalism was a major rallying cry for then presidential candidate Digong (the other was peace and order). We are looking at a leader who is keeping his word.