- How do you get it open?
- Just knock.

6 seconds sound clip from the The Little Shop of Horrors (1960) movie soundboard.

You can hear this line at 00:53:36.704 in the Blu-ray version of the movie.

Quote context

[...]

- OK, let's try this. One... Two... Three... Four...

- I ain't got no more money, honest!

- Alright. Try it the other way around. Five... Four... Three... Two...

- All right! All right already!

- Okay, Big Dad, where?

- In the plant.

- In the plant?

- The big plant, Audrey Jr.

- Inside the big leaf?

- That's right. Inside.

- How do you get it open?

- Just knock.

- In there?

- In there.

- Inside.

- In the bottom.

- I don't see anything.

- Way inside. Right at the bottom.

- Oi, what I did?

- I don't care about you got a date with Audrey tonight.

- I am no more sitting up with that no-goodnik plant.

[...]