How to stop co-routine?

When two co-routine is running.Then how to stop first co-routine?
GLOBALS.stableTime = 5;

IEnumerator StableWaittingTime ()
{
        yield return new WaitForSeconds (1f);
        if (GLOBALS.stableTime == 0) {
                GameManager.instance.LevelFaildMethod ();
        } else {
                GameManager.instance.stableWaittingTime.text = GLOBALS.stableTime.ToString ();
                GLOBALS.stableTime--;
                StartCoroutine ("StableWaittingTime");
        }

}

Take a look at this:

It’s not my work, but I have tested it and is really helpful.

Two methods come to mind

The best method I can suggest is using the string form of StartCoroutine. Then you can call StopCoroutine directly.

StartCoroutine("StableWaittingTime");
StopCoroutine("StableWaittingTime");

The other method is build you coroutine so is automatically aborts when the condition is satisfied.

You can also use yield break for stop co-routine

IEnumerator DoCheck() {
    yield return new WaitForSeconds (1f);
    //Do your stuff here
    yield break;
}