Changing a value in a C# script in a list Objects

My main script:

 public class Take_Cover : MonoBehaviour {
         public float heath = 100f;
         public float rangecover = 3f;
         public GameObject[] cov;
         public GameObject cov_target = null;
     void searchtarget()
     {
       cov = GameObject.FindGameObjectsWithTag("Cover");
       if ( cov.Length > 0 && cov_target == null)
       {
              foreach (GameObject co in cov)
                   if ( in this, i wanna check value "cover" in co's Rock script and if it's true)
                    {
                             cov_target = co;
                             set value "cover" in co's Rock script to false;
                     }
       }
     }

And Rock script:

  public class Rock : MonoBehaviour {
         public bool cover = true;
 

Thank!