Click the
Change It button, which will bring up a standard Open
dialog. Navigate to the new datafiles folder, so that you see the name
of the new folder in the popup menu at the top of the dialog.
Click the
Select button at the bottom of the window, and the change will be made. The
Datafiles menu will be rebuilt, using the datafiles in the new folder.
Checking Your Change
If you get to experimenting with different folders, you may become uncertain about exactly which folder you've settled on.
In that case, you can select
Show Datafiles Folder in Finder in the
Files menu, and the folder containing your folder will be opened in the finder with your datafiles folder selected.