When an order is first created, CORs can be added/removed/modified by pressing Shift-F12 to open the SoftPro Development Studio. At this time, the modules are in read/write mode - you can even add new modules if you wish.
Once the order is saved and the user re-opens the order, CORs are read-only by default. You can still use Shift-F12 to view the CORs, but you cannot edit them nor add new modules to the order. (Note that the module source viewer window has the message "[Read-Only]" appended to the module name.) If you want to open the order modules in read/write mode, you must first open the order with the ALT key pressed. Then you can use Shift-F12 to open the development studio with the modules in read/write mode again.