Make sure your new namespace(s) are created first, before continuing.
To move pages one at a time:
- Go to Administration.
- Select 'Wiki Pages'.
- Select the source namespace from the 'Namespace' drop-down at the top.
- Find the page to move and click the 'Select' hyperlink.
- Use the 'Migrate Page' box to move the page to a different namespace. Select 'Copy Page Categories' to copy any categories to the new namespace.
To move multiple pages at one time:
- Go to Administration.
- Select 'Wiki Pages'.
- Select the source namespace from the 'Namespace' drop-down at the top.
- Click the 'Bulk Migrate' button.
- Use 'Search' to find pages to move. This will only search the namespace you specified on the 'Wiki Pages' page.
- Select each page to move in the drop-down and click 'Add'.
- Select 'Copy Page Categories' to copy any categories to the new namespace.
- Select Target Namespace and then 'Migrate'.
NOTE: Moving pages to a new namespace may break any existing links to the page from other pages.
BTW, this is using the current version of Screwturn (3.0.5.600). Older versions may differ slightly but I believe the functionality has been there for a while.