This explanation isn't helping perfectly. as I have tried doing it but still landing on some errors with contact and constraints.
Is there any way to convert your files and open in Creo 4.0
I don't know of a way to convert from Creo 5 to Creo 4. Also there are just so many steps taken to describe. I can give images... sorry too many words to explain. I will let you ask the questions where it is unclear.