I would transfer the nuc to a BB first , no need to fill out the BB with frames, and leave for 3 days. Then get one large newspaper page and before you put it on the host hive , mark and put holes in the two inner front corners with a straight pin ,you can put plenty of holes in the paper with the pin if you wish. Open the host hive , smoke off the bees of the edges and put on the newspaper, keep the paper in place with a eek or an empty super.
About one hour before you combine the hives brake the seal between the BB you are going to move and its floor. Braking this seal can agitate the bees so best to have it done a while before you combine so they will be nice a quite. I like to take of the roof off the BB l am moving ,just keeps thing light so l make sure the crown board is secure and the hole in it blocked.
Then when you are ready to combine gently take off the roofs and nice and easy lift your BB onto it host BB no need to use smoke or water spray . You will have to do this early in the morning or late in the evening
If you are doing it early in the morning you can set up the paper on the host hive the evening before. When together leave for 6 or 7 days before you open up and fix up the frames.
What ever way you combine l hope all goes well.
Regards.
Liam C