We got a call last year from an elderly couple with 40 decorative birdhouses in their small backyard. One had honey bees. A delightful couple, and we were happy to help them out.
I put a pill bottle in the entrance hole, put a piece of OSB (wood) on the bottom and fastened the house to the OSB, then took it home, much like NS did above. A few weeks later, a retired Physical Therapist and new beekeeper, Crosby, and I did the cut out. Here it is before we started...
We started by removing the shingles for access to the top of the combs. We were able to use a medium sized serrated knife to cut the comb from the roof, one comb at a time.
First look at the brood nest showed a spotty pattern with mite guano in the cells. They needed to be treated (with OAV).
It was a banner day for Crosby and his first cut out. He secured the comb into frames with rubber bands then placed the frames inside the NUC box with a feeder.
The bees had moved down into the bottom of the bird house during the cutout, so we let them march into their new home. I might have used a couple drops of lemongrass oil on top of three frames to increase interest in their new digs, plus a little smoke behind them to get them moving out of the birdhouse. They did go in eventually. A good tactic, if you catch the queen, is to put her in a queen clip and place her in the new hive box. They will move more readily if she is inside. Her confinement there insures that they will not fly away.
Job done.