What has proven to work for us is to leave him in his crib after he wakes, to play a little bit by himself. I am using 15 minute intervals and Grayson actually seems to be adjusting just fine to the new wake times. I hear him get up and coo and play, so I leave him for fifteen minutes longer each time he seems to have adjusted. To be more consistent, you can do this for three days and then increase it by fifteen more minutes for three more days, etc. And I am feeding him right when he wakes up too, so this is moving his feed and wake time up a bit. It works!
Jessica with Grayson - 16 weeks