Several great ideas above for sure!
Shown below is the 20ft long pipe with a crowbar taped to the end for shaking high branches, (If you look up and to the right of the top of the pipe, you will see the swarm). If you can wait, do this early in the morning while the bees are at their coolest for the day and enough bees will drop to the ground to get things started. In this case, I shook the limb in late afternoon, but many of the bees went back to their branch. The early morning shake did the trick.
Sometimes, when the swarm is 20 ft up in a tree, I will spread an old bed sheet on the ground directly under the hanging swarm to help bees focus on the new home you are offering them. Once they start marching toward the new home, they will all go in.
With bees already on the ground and milling around or marching into the box, several more shakes may be necessary to dislodge bees that return to the branch and the scent left by the queen. Once the queen is on the ground, you have a good chance the bees will hive themselves as shown below. This isn't my idea, I saw JPtheBeeman do this on TV.