What i used to do with my DS, was feed him at 4-5ish am when he woke up humgry, and then i set my alarm clock at 7:30 and feed him his "breakfast" then, i didn't care if it was only a few hours past the nigth feed, 'cause if i didn't wake him at 7:30 or hole day was thrown away, so it worked really well. He cutted the 1-2ish am feed at about 12 weeks, and when he started waking up (after cutting the 1-2ish am feed) hungry at 6am i gave him only 1 or 2 oz, to hold him off until his "breakfast" at 7:30
Hope this helps