Android ADT 23 Update - Cannot complete the install because of a conflicting dependency

I was facing the same issue and resolved it by uninstalling the previous version of ADT completely and then installing the new version.

Try it out.

It works for me :)

If for some reason you installed an ADT preview and need to revert back to the current stable, you can't use the dialog to install "new" software since what you want is actually an older one. Instead do this:

• Open Help > About Eclipse... on Windows or Linux. On Mac, use the app's menu > About...
• Click the "Installation Details" button.
• Select the "Installation History" tab.
• Select one of the previous configurations.
• Click the "Revert" button at the bottom.