Reset Mysql Database?

My Cloud OS 3 Personal & Network Attached Storage My Cloud EX2
1

Hi,
in the past I installed joomla, phpmyadmin, phpbb and others - now i want to reset the mysql database which is located in /mnt/HD_a4/.@database@/mysql

Does anybody know how to do that? I already tried:

  • factory reset
  • firmware reinstall

Both is not affecting the mysql database …

Thanks in advance!