It's tricky to merge chicks. Many folks just wait until they're the same size because it's easier, but I actually begin merging mine when they're two weeks old.
You will need to build a "panic room" in the run. My first panic room was a simple enclosure I rigged in a corner with chicken wire and 2"x4"s. Make it at least 4 feet by 2 feet for six chicks. If I count accurately, you have six, right? Make it larger if you can, to accommodate a pet carrier. Cut a couple of portals 5"x7" high into the sides. Make it so you can open and close them easily. Leave them closed for now.
They are going to need to acclimate both to the outside weather as well as the older chickens. Put them in the carrier and take them outside during days that aren't real ugly. Place food and water in the panic room, open the carrier and leave them there.
They'll come out in a while and explore, using the carrier to warm up. Take them back to their brooder at night for the first couple weeks. After the first week, open the portals to the panic room and let the chicks explore the big run. The adults will probably chase the youngsters but they will very quickly discover they have safety in the panic room, thus its name. If your run is complex like mine, with divided areas, I cut portals into any fence or wall where the chicks might get cornered or trapped with no means of escape. This is crucial when merging small chicks.
As long as they have a safe area to escape back to, chicks do extremely well with adults. But do supervise during those first couple days and play it by ear.
To merge them into the coop, this is way more stressful on them and you. But it can be done. I wait until all the hens have finished laying and then I install the chicks in the coop and close it up so they don't get out and the adults can't get inside. Wait until they're real comfortable in the run, maybe the end of the second week.
At the very last minute before roosting time, I let the adults inside. They usually won't mess with the chicks if it's almost dark. Try to place the chicks either on the perch or in some spot where none of the adults is used to roosting. This should go pretty much without incident. My first chicks were six weeks old when they moved into the coop with two adults, and they commandeered the best spot on the perch, but the two big girls didn't mind and left them alone.
In the morning the chicks will get chased outside probably, but you will want to be there to watch over them just in case. They will know to run into their panic room by now, so they'll be fine in the run. Getting them to go into the coop at night is going to be arduous. You will need to teach them to do it. If you've taught the chicks to come to you already, I just get inside the pop hole and call them. As it gets darker, they will want to follow my voice, and they come in. Or you'll need to chase them down and put them in through the pop hole.
It takes a week to two weeks for them to learn to go inside on their own. Expect it. Deal with it. There's no real easy way. It takes time for them to learn. You might enclose them in the coop for their first several days of living in the coop, following my instructions for the first day. That should help imprint on them that this is their home.
A lot of people will tell you to wait. But it can be done. It's just not easy. If any of the adults are particularly bullying, you'll need to come back and tell us so we can maybe help with that. But keep us posted anyway. This will be a major event in your chicks' lives! Yours, too! Good luck!