How do I destroy an especific instance on the game?

i am creating a tank with 2 parts:

the first one is the body, who moves in the layout;

the second one is the cannon head, who aim and shoot;

i'm creating the death process, when the enemy life turns 0, the tank is destroyed (body and head).

but when i destroy the head, all the heads in the game are destroyed together.

summing up: i want to destroy a tank's body with it's especific head, without destroying all the other heads in the process.

Read up on Containers.

thanks!