How do you push back bedtime?

My 5 months old and is waking around 4am most days and 5 am if we’re lucky. I’ve read that I should push back his bedtime by 10 minutes each day. But there’s no guidance on what that looks like. At the moment he gets cranky around 6-6:30 and he falls asleep after a few minutes of being held and bounced. I’ve been going with his cues to make sure he’s not overtired. Do I just let him be cranky and hope that doesn’t push him into being over tired?