Shut down your VM's, make a backup of them, start the VM's, uninstall the Parallels tools, shut down the VM's, run the 3188 uninstall script, reboot your Mac, install 1970, start your Windows VM(s), install Parallels tools. The uninstall script is available to you only after you mount the original Parallels 3188 dmg file that you downloaded from the vendor.
