You can't save an Access database as anything other than an Access database.
You can, however, save the individual tables within the database as either
..dbf or Ascii delimitted (not sure about .dif)
Through the GUI, select the table, go to Save As/Export and pick "To an
External File or Database". Pick the appropriate value in the Save as type
list. In some cases (like Ascii delimitted), you'll be presented with a
wizard to help you complete the export.
Programmatically, you can use the TransferDatabase method.