Step 1: Login to cPanel and click on ‘phpMyAdmin’ under databases section
Step 2: Choose the database of your joomla site and click on ‘Export’ then ‘Go’
Step 3: Locate the Exported sql file that was saved on your Local PC and open it with a text editor.
Step 4: Go to the Find and Replace option on the notepad and find the string ‘jos_’ then replace it with your new prefix
Step 5: Now click Replace All, then save the file.
Step 6: Import the edited notepad file in sql format via import option of ‘phpMyAdmin’
Step 7: Now update the new database tables prefix path on the ‘config.php’ file of the Joomla installation.