You need to start to extend his first A time of the day.
If you reread the link I sent you, your DS applies to #3, which is he takes two naps but wakes earlier and earlier. True?
So, what this means is that he needs more A time and less day sleep. This is why you shorten the AM nap. Since he's also an EW, you start to move that first nap by 20-30 minutes.
Once you do this, it may take at least a week for his body clock to adjust. Don't expect to see immediate results - especially with an Early Waker!
You may also find you have to juggle the A times, as he may start to get sleep sooner than previously. Just keep playing with it. It's an art not a science!
Let me know what youthink,
Lu