public void ChangeLabelText(System.Windows.Forms.Form form)
{
if (form != null)
{
var labelIdWhoseTextNeedsToChange = "label2"; // Or any dynamic logic to determine which label will have to be updated.
var labelControl = form.Controls.Find(labelIdWhoseTextNeedsToChange, false);
if (labelControl != null)
{
form.ChangeLabel("Surname", labelControl);
}
}
}