Creating/deleting Stadium Parts?

[LegoKOBE]

How it is possible to create new stadium parts with oedit, or to delete some parts. I can only move already existing parts with oedit, but can not create new ones or delete some. Which programm do i need for this. Mayby Superman can help, because he brought in the new Lights in the Streetaddon Court and the new long bench. I really hope someone can help me!!!