You lock them in the coop at dark. The next morning before first light go out and take them off the roost one at a time and dose. After dosing each bird put it in the run. When the coop is empty, you have done them all. It's much easier this way. If any struggle and protest, you can wrap them in a towel to hold their wings and make it a little easier. A helper makes it easier too, but I do it by myself every time, 2 -3 dozen birds every three months. It's not as bad as you might think and it gets easier with practice.