Take Air Freshener.
(I use AirWick 6 in 1 with100% Natural Propellant "Premium Fragrance, acts in seconds, lasts up to 1 hour, Inspired by Natural OIls, " ) (Ivory Freesia Bloom but other scents will work just as well)
Spray on top of frames of lower colony . Then take upper colony ,tilt to one side and spray on bottom of frames. Duration of spray ? I use 4-6 seconds.
Temporarily blocks sense of smell. Bees go all buzzy.
Unite.
Walk away.
Leave 24 hours
Done.
No faffing round especially in windy days when paper tries to fly away..
Also used to add one (or more) frame of bees to a colony. (Spray both sides of frame and colony top frames plus gap where frame is to be inserted.)