Download the latest version of LiteIcon. Right click to show the package content
Go to Contents, Resources and copy, paste and change the name from IconData_10.11.plist to IconData_10.12.plist.
Open it and search and change all 10.11 to 10.12.
reboot into recovery, disable SIP. change icons, log out. reboot back into recovery, re-enable SIP....
works!