Installing Apple Remote Desktop Admin 3.0 if a later client version is already installed

Issue or symptom

The Remote Desktop 3.0 package installer will not install on a computer that has a later (newer, that is) client version installed.

Solution

1. Uninstall the later client software. See this article for detailed steps.
2. Install the admin and/or the client software using the Apple Remote Desktop 3.0 Installer.
3. After installing ARD 3.0, use Software Update to update to the latest version.