How do you shorten the amount of frames a drawing is on?

[Edahel]

I can expand how many frames my drawing will be by clicking on the little gray thing next to it and dragging it up to where I want, but I noticed it doesn't work when I want to bring it back. That means if I expanded a drawing on 10 frames but then I want to shorten it to 5 frames only, I can't. Why is that? How can I do it? 

For now the only way I found was to manually delete the frames I don't want and then moving aaaaall the other drawings back in place. That's time consuming and annoying, especially when you want to test out several durations :(

[Edahel]

Wanted to say I found the answer to my own question so if anyone has the same issue, here's what you're missing:

You have to actually select all the frames your drawing has been extended to, then it'll work. Basically it can only remove the frames after the one you've selected so if you just selected one, it's not going to be able to do anything else than extending it.

[Artisteacher]

You can also use cut - ctrl+X.