Convert tags to list, then back to array

Heres what I’ve got:

List<string> lst = UnityEditorInternal.InternalEditorUtility.tags.OfType<string> ().ToList ();
lst.Add (selectedTag);
foreach (string str in lst) {
		Debug.Log (str);
}
UnityEditorInternal.InternalEditorUtility.tags = lst.ToArray ();

I understand the list updates because Im creating the list and storing info into it.
Its the last line of the above code that gives me a read only error.

So how can I overcome this?

You can’t assign to the tags property because it doesn’t have a set method. Apparently you can assign a tag but it looks to be a bit of a pain, there’s an answer about it here.