For all fools who accidentally modified iCloud Keychain password entry, I finally found a way to restore the state of the iCloud Keychain to an old version
You have to have a backup of the ~/Library/Keychains folder (either by your own or by Time Machine snapshot). If you don’t, you cannot use this method, and I doubt that iCloud would store any deleted or modified password.
1. Turn off any network access.
2. Restore the folder inside ~/Library/Keychains that have the UUID folder name (something like 1234567-1A12-1A12-2AAA-12A23B34C45D56) into ~/Library/Keychains, and select the option “keep both” (do not replace the original folder and do not use the original folder name)
3. Modify the original folder to another name.
4. Logout and login with **another account with admin access right**
5. Modify name of the restored folder back to the original name.
6. Logout and login back to your account.
7. You should get back your old state of iCloud Keychain. And do not mess up again!