Remove HQbird Server and/or Admin tools. Administrative rights are required. Copy databases and configs out first if you still need them.

Windows

Control Panel → Programs → Uninstall a program. Select HQbird Server Side and/or HQbird Admin and uninstall. Needs an administrator account.

Linux

With sudo, run:

/opt/hqbird/uninstall.sh

This removes HQbird from /opt/hqbird and Firebird from /opt/firebird, plus autostart service files. It does not keep the HQbird configuration, and it removes Firebird binaries, configuration, and the firebird Linux user.