You just make the hole in a tree and put the straw inside, and the tree starts leaking drop by drop. You can leave the jar attached by rope to the tree right below and come back after couple of hours.
What probably not every source is saying, it's important to cover the hole later, so the tree does not get easily infected. In a long term it may hurt the tree.
Drill would be perfect for that. All I have is not-so-sharp knife, so I would sweat more liquid, than I could possibly collect :D

Difficult to tap the branch, but I'm sure the tree was fine. If it would be so fragile, it would extinct with all those animals into the wild :)