I have already said that everbody's situation is different and if you need rooster you should keep him. And like we all said, wait for pullets to start laying, then you should introduce them to the flock, and you should first put it in the tractor, just like you did before and wait for maybe a...
Everybody's situation is different so you will have to decide on your own. If you think that you need them, just wait for the pullets to start laying so you can be sure that rooster won't do any bigger damage.
I agree with @CTKen, you should get rid of him. He can become serious problem, especially with cockerels in the batch, since they are not that young anymore.
And if you want fertile eggs you will have them when your cockerel(s) grow up.
And I would never introduce them during the night. Had a...