Step 1

Create a file named 

ews_make_backup.txt

one an USB flash drive, in its root directory.

Step 2

Insert the USB flash drive in one of the free USB ports of the EWS.

Step 3

The EWS light will go off. Wait until the light returns to its normal blinking. Then pull the flash drive.

Step 4

Open the flash drive on any computer. Check if there is a folder called "ews_backup". 

The ews_make_backup.txt should be renamed with the prefix "_failed" or "_success". Which indicates the outcome of the backup.

For futher diagnostics open the ews_make_backup.txt... file with a TextEditor.