Try going to File menu/Print and see if Adobe PDF is in the menu for Printers. If so, select Adobe pdf as the printer and click on the Output section. Under Color select Separations. Do any necessary settings and print the pdf separations.
I'm not sure if the Adobe PDF "printer" is installed by Indesign or Acrobat so, if you don't have Acrobat, I don't know if you can do what I described above.
Using OSX 10.3.8 on a G4