one more thing you could do is. open workbook on server>>>>click download>>>>>select data>>>>go to full data>>> select show all column>>> download all row as text file
now download the workbook create a new data source with a text file you just downloaded. select create an extract
after completion, select replace data source
and it's done.
With a live connection you will not be able to download the data with a Tableau workbook. For this you can follow this pocedure :
Create an extract connection in your workbook and publish it in the server with an refresh schedule to it (As per you Data updates). Now whenever you download the workbook it will come with the last refreshed data with it.
Hope it helps :)