Hellobee Boards

When he wakes up at 6:15 a.m. are you giving him a bottle then? I'm thinking keep the 6 oz the same, and start cutting down the 4/5 a.m. one. If he's getting a bottle as soon as he wakes up, he might start stretching it out until then.

This sounds exactly like my son when he was 3-4 months. Same wakeup times and same amounts of formula.
My ped told me to tackle the 12/1 feed first. I did that one slowly. I think I decreased .25 oz every night. He barely missed it! He was exactly the same if he had 5oz or 1oz. That's how I knew he truly didn't need it. But it's important that once you decrease the amount to never increase it again! And once it's gone it's gone. Paci, paci paci! (If he takes a paci).
The 4/5am my ped had me do more aggressively. He was also having 5oz and she told me to decrease by an ounce each night! And by the 6th night when there was nothing left, let him CIO. We had to let him CIO for 3 nights and then he was sleeping 7p-6a!
And fwiw, this was at FOUR months that my ped told me to eliminate that 4/5am aggressively, saying he didn't need it and it was habit. So glad we did!

ETA: I would take a look at 12 Hours by 12 Weeks. I read the parts relevant to me in an hour, it's very very short. It is controversial, BUT 1) You are well past 12 weeks so I don't think anything in there is radical for a 6 month old and 2) just like any advice, you can modify it to what you are comfortable doing. I read it and modified it to what I was comfortable with and with my peds input (which was very comparable to the book). We were also a little past 12 weeks when I first read it so it wasn't as aggressive as we were already on a 4 hour schedule, he was already drinking 24oz, etc.

@Littlebit: Yes! I love the Troublesome Tots site! I used that a LOT when we were working towards eliminating night wakings! When we did, we still had a 5 or 6am wake up a lot of mornings (which, whatever, i'm up at 5 for work) but she did eventually stretch it out to 6:45 and 7:30 on weekends if we let her!Fussing is good! Maybe you'll skip the CIO phase (although that was a 20 minute thing for us, so totally NBD)

@Littlebit: E woke up and we'd give a paci and just kind of rub her chest a little. We had to CIO once we moved her to a crib. But there was more going on than just night weaning from her bottle.