It's been long enough that, even if the coop is fine, they may associate the coop with being grabbed and tossed about. It doesn't matter if you do it nicely or not, they're not going to like that (at least mine don't). Try luring them in with something delicious. I would suggest doing this at least an hour before sunset, so they won't "suspect" anything. Lock them in for the night then. Do this for a few days, see if they get the idea.
Assuming that the coop is well-ventilated and so forth but they decide to be stubborn still, you may have to keep them locked in the coop for a few days. Make sure they've got plenty of food and water and aren't too hot, but don't let them out for a while.
Mine didn't like their coop either at first. I had to go out and toss them in during a monsoon storm. That wasn't exactly fun for any of us! I kept them in there for a good 36 hours or so. With the rain still coming down, they realized pretty quick that the coop was MUCH better than just sleeping on the ground. Now I don't have any problems with them putting themselves to bed.