Pole pruners--a saw on a long handle--are used to cut branches that are too high in a tree to be pruned without a ladder or extension. Pole pruners are often used in situations where a ladder is dangerous, impractical or inconvenient. Although some have a lower jaw to lock the blade to the tree as you saw, in their most basic form most are simply a saw blade on a handle.
Extend your pole pruner to the approximate height of the branch to be pruned. Many pole pruners have telescoping aluminum shafts that are tightened via a twist mechanism of a lever that flips up and down. Be sure the sections are secured before raising the pruner.
Check the height of the pruner by laying the blade on the branch to be pruned. By not over- or under-extending your pole pruner, you are able to apply more pressure to the cutting mechanism.
Place your pruner's saw on the branch as close to the branch collar as possible. Try to angle the pruner so the cut is at a similar angle to the branch collar.
Use the handle on the pruner to saw through the branch. Make sure that your pole pruner blade is wide enough for the thickness of the branch you are cutting. The blade should be at least twice the thickness of the branch, but three times the thickness may make cutting easier.