I haven't heard of many people who have had success with shortening their day sleeps so they sleep longer during the night. Sorry.
Like Arcadia has said, how dark is his room at 5.30am? How noisy?
Emily sleeps 12-13 hours at night, and 4 hours during the day. Even if she was to be woken earlier during her day sleep, she will still only sleep max 13 hours overnight.