You don't rename an item. You simply set it. If you've added the text "Hello World" to your list and its at index 3 then you simply change it by setting the item at index 3:
VB Code:
  1. myCheckedListBox.Items(3) = "Goodbye Cruel World"
The Items property of a CheckedListBox is just a collection like any other, so you manipulate the items it contains like any other collection.