Bees can settle anywhere, especially difficult to get to places. Ask yourself whether climbing up a couple of metres is safe and evaluate whether the bees are worth catching. Place an empty box directly below the swarm. Sharply shake the branch downward or scrap the bees into a square plastic container and place in the empty box. It is important to dislodge the majority of the bees in the cluster. Sometimes it doesn’t work and the bees take flight and re-cluster in the same position. Try again.
Once they have settled in the empty box they can be transported and shaken directly into their new home. Bees have full stomachs of honey ready to build comb and prefer to cluster for a while. Put an empty super beneath a super of foundation. When they finish clustering, they will move upward onto the new frames of foundation. Because of their desire to construct comb, swarms are excellent at drawing out foundation. Remove the empty super a day or two latter.