I've used Central Files a little bit and I'm pretty sure you can. My best understanding is as follows:
If you are not in the central file you do have the option to "Save As Central File". This will make the new saved file the Central File. Previous local files will NOT be linked to this new Central File, new files will need to be created for each user the same as with the old Central File.
You can Save As a current Central File to a new Central File, but agin the local files will not be linked to the new Central File. There should be no other problems with copying it. You should probably make sure that everyone on the team is aware to use the new Central File. It might be a good idea to make sure any borrowing and such is cleared as well, just in case.