(see also http://forums.seagate.com/t5/GoFlex-GoFlex-Desk-GoFlex-Pro/How-can-I-un-install-Seagate-Diagnostics-... )
run the installer (link below), choose "customize", uncheck the box for installing the software, and check the "uninstall" box.
http://www.seagate.com/staticfiles/support/downloads/goflex/Seagate%20GoFlex%20Software.mpkg.zip
to manually uninstall:
- Go to your Applications Folder and locate the Seagate Diagnostics application. Delete it by moving it to the Trash Can. It will ask you for your password. Provide your password and the app will be placed into Trash Can.
- Go to hard drive and open it. Go to the Library Folder and open it. Go to the Application Support Folder and open it. Locate a folder called Seagate. Delete it by moving it to the Trash Can. If OS X asks for your password, provide it, and the folder will be placed into Trash Can.
- Close the Application Support Folder. Go to the LaunchAgents Folder and open it. Locate the com.seagate.SeagateStorageGauge.plist file and delete it. Again, OS X may ask you for your password.
- Close the Application Support Folder and then the Library Folder.
- Open the System Folder, then open the Library Folder. Locate the Extensions Folder and open it. Locate the Seagate Storage Driver.kext and delete it. OS X will ask for your password again. Close all folders.
- Reboot your Mac. When it finishes rebooting, you can now empty the Trash Can.
