I cut strips and customize them to the individual area at the workface. Sometimes, instead of strips, I roll the screening into narrow cylinders, and wedge them into place. If I happen to see a female bee enter a gallery, I will treat the gallery while she's in there and continue with the screening process. Everything has to be checked at a later date, as the bees are quite robust and can possibly dislodge the screening or find another way in. You get better at it after a few houses.
Professional help is usually needed here, it can get dicey.
If you do call, ask for, or leave a message for John. Best time to call is before 10am and after 3pm. Other times I'm often out on the road. Due to the expense, and the volume of calls I get, I can't always return a long distance call. If you want, however, you can ask the office about a time when I am expected to be in, so you can then call back.