Trying to Access Components of an Object in another class

I think my C# is a bit lacking here but I am trying to access a component in a list of objects in another class. I am trying to access UnitController from MultiSelectClient and I'm not sure how to do this. I can remove the objects from the list but I can't seem the access each one even if I try a ForEach loop, I can't wrap my head around it.

UnitController.SelectedUnits //Is the list I'm trying to access.

Ive tried doing

UnitController.SelectedUnits.Find/FindAll(gameObject)//but that returns an error

This is where the list is defined

public class UnitController: MonoBehaviour
{
    bool clicked = false;
    bool dragging = false;
    //public float speed = 10f;
    //public float rotationSpeed = 10f;

    public LayerMask groundLayer;
    public NavMeshAgent playerAgent;

    public static Vector3 mouseDownPoint;
    public static Vector3 mouseUpPoint;
    public static Vector3 currentMousePoint;

    public static Rect selection = new Rect(0, 0, 0, 0);
    private Vector3 startClick = -Vector3.one;
    public Texture2D selectionHighLight;

    public static List<GameObject> SelectedUnits;


    public RaycastHit firstRay;
    public RaycastHit secondRay;



    private void Start()
    {
        SelectedUnits = new List<GameObject>();
    }

This is the script that needs to access it. At least I want to be able to iterate through the list and access each unit in the list and its components.

public class MultiSelectClient : MonoBehaviour
{
    public bool Selected = false;
    void Update()
    {
        if (Input.GetMouseButton(0))
        {
            Vector3 camPos = Camera.main.WorldToScreenPoint(transform.position);
            camPos.y = Screen.height - camPos.y;

            //if inside the cameras drag selection area then mark player as selected
            Selected = UnitController.selection.Contains(camPos);

            Debug.Log("Selected");
            if (Selected)
            {
                addTo();
            }
            else
            {
                UnitController.SelectedUnits.//something
                UnitController.SelectedUnits.Remove(gameObject);

            }
        }


    }
```