Carl
A trapout can be one of two types (Hogan vs cone) and can be left in place for different lengths of time depending on what you want to accomplish. If you want foragers, house bees, and maybe a queen, use a Cleo Hogan trapout. I use this technique when I don't want to remove the hive from the tree. I can steal 8 deep frames of bees multiple times a year and use them to start a new hive or boost a weak hive. This Cleo Hogan trapout requires creating a short dark tunnel from the tree hive entrance to the back of a super. It is baited with a frame of larva without any bees on it. The houses bees come out and collect on the brood frame. Foragers also collect and deposit pollen and nectar. With frequent checking, a queen can be found in the super. The other mesh cone trapout has been explained above and traps out foraging bees. The queen will abscond and you won't be able to capture her.
If the owner doesn't mind the tree hive, do serial trapouts which is a great source for free bees.
Check your trapout multiple times at first to make sure the bees have no way to get back in to the tree hive around the mesh cone or solid tunnel. I hammer in a metal ring custom made by my partner around the entrance to the tree. I attach the mesh cone to this or push the back of the super which contains a 2 inch hole up against the ring.
Trapouts are a lot of fun so enjoy!!