How do people kill humpback whales?

Answer 1

Harpoons are still a favored choice.

Essentially a long bladed spear attached to a rope.

In the old days they would be hand held

Modern versions are shot from an air pressure release, deck mounted, harpoon cannon which than reals in the dead animal and pulls it along side so that it can be netted or tied for transport, or pulled up on to the deck of larger whaling ships where it can be gutted and disemboweled on deck