Download MSI/DMG: https://www.gimp.org/downloads/
Installation:
gimp-x.x.x-setup.exe /VERYSILENT /SUPPRESSMSGBOXES /NORESTART
Uninstallation:
"C:\Program Files\GIMP 2\uninst\unins000.exe" /VERYSILENT /SUPPRESSMSGBOXES /NORESTART
Recommendation: use your distro's package manager.
Installation:
apt install -y gimp
Uninstallation:
apt remove -y gimp