NX Is it possible to remove manufacturing data from a prt file?

Is it possible to remove all the CAM information from a prt file, either to rebuild it from scratch or to simply clean it from the file completely?

Yes, there is a specific command for this purpose.  

In NX2212 and up this command can be found here:

     Menu; Tools; Resource Bar Tabs; Operation Navigator; Delete Setup

In NX2206 and earlier, the menu structure is slightly different and the same command can be found here:

     Menu; Tools; Operation Navigator; Delete Setup

In either case, this command will completely remove the CAM setup from the file, including removal of any library machine loaded into the setup assembly, and present the user with the standard Machining Environment dialog to select the CAM configuration to define a new setup.  If this dialog is simply closed without defining a new CAM configuration and setup type, the session reverts back to the Gateway application and there is no longer any CAM data in the file.