The RemoveLayer method removes the argument layer from the calling Camera. This method should be called on any Layers manually added to a Camera in custom code.
The following code shows how to add and remove a Layer from a Camera (the Camera.Main, specifically):
// In the Screen - add the Layer as member Layer myLayer;
// Create the Layer in CustomInitialize: myLayer = Camera.Main.AddLayer();
// Remove the Layer in CustomDestroy: Camera.Main.RemoveLayer(myLayer);