Agree with the others, but I'd suggest not doing it after dark, but at dusk, when it's dark enough that they want to start getting ready for bed, but not so dark that they can't see anything. Ideally they'd be able to see where they're going and where you are putting them. Wait until dusk, when the other chickens have just gone in (the new ones watching the existing flock go in will help them learn, too), and then manually put them inside through the pop door. Close the pop door, go in through the human access door and put them on the roost. What's your roosting setup? Do you have multiple roosts or just one? The flock may not be okay sharing a roost with the newcomers, even if they seem to accept them during the day. The newcomers might be afraid to roost because of that. Ideally you'd have a separate roost for the new birds, until they are fully accepted into the flock and able to share a roost without squabbling. So when you go inside, put them on a second roost manually. By then it will be dark enough that they probably won't risk jumping down, and will stay put, but not so dark that they can't see anything. So they'll see where they are, and start learning that that's their place to sleep. Do this for a few nights and they'll eventually learn. I just did this with my new chicks and they figured it out in 4 days.