Make sure to check which version of JetBackup is installed on your server first.
To uninstall the JetBackup V4, run the command line:
yum remove jetbackup-core -y
To uninstall JetBackup V5, run the command line:
jetapps --remove jetbackup5-cpanel
For the DirectAdmin server, run the command:
jetapps --remove jetbackup5-directadmin
Removing JetBackup repo from CentOS/RHEL:
yum remove jetapps-repo -y
Removing JetBackup repo from Ubuntu OS:
apt-get remove jetapps-repo
That's all!