How to stick my left side of the headphone?

Jonathan, can you clarify your question? All you've told us is that it's broken; we're going to need a better description of the problem if you want help.

Specifically, what part of the headphone is broken? Do you mean the speaker doesn't work? Has the headband part snapped? Is the earpiece separated from the headband?

As you can see, there are several things that could be wrong that could all be described as "broken" and they all have different solutions, so it's important to be precise with your question so we know how to answer you.

Pictures of what's broken are generally helpful as well.

Adding images to an existing question