a) Login to your websites CPanel
b) Search for Backup option and click on it
c) Now here on this page Click on Generate/Download a Full Backup
d) Under "Backups Available for Download", click the link with the file name of the backup.
e) Once you clicked on it , it will start downloading the backup file
f) Select a destination on your PC for where you would like to save it to.
g) Click Save