If you think he is ready, try tracking when he does wake up at night. If it is consistently at the same time then use the wake to sleep method (it worked for me). Also, I would put him in one f those sleeping bags instead of a blanket if he is getting out of it. THat should get rid of that problem so perhaps he would sleep longer?
I weaned my son off the night feed doing the following:
Whenever he wakes the first night, feed as usual. The second night, do not feed him until at least that time or later. Carry this on (you should get the nightfeed moving later and later, ie, 4am, 4:30am, 5am). It may mean you spend a few nights spending time at 4am trying to get him to sleep, but it is worth it in the long run. In addition, I also slowly cut back the size of the nightfeed. The first night I let him take whatever he wanted, then every 3 nights I cut back on ounce. It will take a couple fo weeks but you should get a baby who wakes at 5/5:30am and only eats 2 ozs. Then you can cut it out.
I know people who have done the hard approach where you don't feed them but I couldn't do that. Plus, I know people who have done it and then it backtracks after a few weeks. The gradual approach also allows you to see if the baby is ready for this as if he isn't, he'll keep waking up earlier or cry until you feed him more. If he is ok with it, after 3 nights he should adjust naturally.
Good luck!