This question may look like a duplicate of: How to uninstall postgresql on my Mac (running Snow Leopard) however, there are two major differences. I\'m running Lion and I\'m
I was not able to uninstall PostgreSQL 9.0.8. But I finally found this. (I installed Postgres using homebrew)
brew list
Look for the correct folder name. Something like.
postgresql9
Once you find the correct name do:
brew uninstall postgresql9
That should uninstall it.