1. Hold down the shift key and double-click on the Deep Freeze icon. Alternatively, you can press Crtl-Alt-Shift-F6. You should now see a password dialog.
2. Enter your password and click OK. If you have not yet entered a password you should be able to click OK without entering anything. You should now see a dialog with boot options.
3. Select "Boot thawed" and click OK. This will disable Deep Freeze on the next reboot.
4. Reboot your machine. After the machine reboots you are ready to uninstall Deep Freeze