MAMP evidently creates some configuration files that can't be wiped via the uninstaller. I was able to circumvent the The privileged action failed error and completely uninstall MAMP Pro using the following steps:
Delete the appsolute directory from /Library/Application Support , which contains configuration files that are created upon MAMP Pro installation
Delete the file hosts.mamp.bak in /etc, which is the MAMP hosts backup file
Delete the MAMP directory from /Applications/MAMP
Open the MAMP Pro Uninstaller, check all five options, and click to uninstall
This should completely wipe the existing MAMP/MAMP Pro installation and enable a clean, fresh install. You may need to restart your computer to get Apache running after re-installation.
MAMP PRO saves its settings per user. The resulting configuration files are preserved after deleting the MAMP folder and MAMP PRO application. To completely remove MAMP PRO including all configuration files, please use the Uninstaller, which you can find in the installation image of MAMP PRO.
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