On YUM-based systems

1. Check whether there are any existing packages:

shell> rpm -qa | grep -i mysql-community
mysql-community-libs-8.0.3-0.1.rc.el7.x86_64
mysql-community-common-8.0.3-0.1.rc.el7.x86_64
mysql-community-client-8.0.3-0.1.rc.el7.x86_64
mysql-community-libs-compat-8.0.3-0.1.rc.el7.x86_64
mysql-community-server-8.0.3-0.1.rc.el7.x86_64

1. Remove the packages. You may be notified that there are other packages dependent on MySQL. If you plan on installing MySQL again, you can ignore the warning by passing the --nodeps option:

shell> rpm -e <package-name>

For example:

shell> sudo rpm -e mysql-community-server

1. To remove all packages:

shell> sudo rpm -qa | grep -i mysql-community | xargs sudo rpm -e --nodeps
warning: /etc/my.cnf saved as /etc/my.cnf.rpmsave