Having done this myself, I was lazy and kept my installed Poser 4 and installed libraries. I then told Poser 5 to look in my Poser 4 directories for figures, lights, poses etc... Finally, I copied the poser library called !DAZ to my Poser 5 library folder (this is essential if you don't want to be prompted for poses when you load Michael, Freak or Victoria 3. When I install new items I either use the regular installer that Daz provides or if it is a vendor, Stuffit Expander, MacConverter, MacInstaller and copy any changes to the Poser 4 !DAZ folder to the Poser 5 !Daz folder (you will know when you have to when the file contains inj or rem files...