If you import from Boot Camp you still have the Boot Camp installation. The instructions are to ensure that your virtual hard file based Windows runs properly, and only then consider removing the Boot Camp partition.
If you don't have the Boot Camp partition with windows on it I do not believe there is any way to move from a Parallels virtual hard drive installation to a Boot Camp installation. You would need to use Boot Camp Assistant and the Windows CD to install the correct drivers, etc. to have a Mac that can boot directly into Windows.