I had a similar problem. I just waited until they went to bed for the night, then took them to their (new) coop. Since it was cold with 6" of snow on the ground, I just locked them in for a couple of days. Now they willingly go in--it's much warmer than roosting 20' up an apple tree! I also feed and water them in the coop, so they have to go in during the day. That said, I would check the coop out first. They could be startled by mice/rats, little birds, predators (eg cats, snakes). They may not like their bedding, especially if its been changed, or if the coop has been rearranged. Unbeknownst to me, a leak had occurred and the floor under the bedding was soaked and muddy. They were much happier after I fixed that. You may consider getting down to bird level......? Also, each flock has a "bedtime" leader that tells everyone when it's bedtime and where to roost. Finding out who that is would be helpful. Since everyone else is just following her lead, you may just have to convince her. Good Luck!