I'm having troubles with Minecraft and I have reasons to believe it has something to do with the fact that I've changed some files in it. I don't really care about keeping those changes and I need to perform a fresh install of the game.
I've tried removing the .app bundle file from /Applications and re-download the .dmg from the original website, but somehow that doesn't count as a fresh install (as my worlds still appear in the single player world list).
So: how can I do a fresh install? (I've already back-upped everything I need)
Best Answer
Uninstalling anything from a Mac can be challenging. Here's how to do it, though.
After going through the steps you've previously outlined of deleting the actual app itself, do the following:
In finder: Hit shift-command-G. Type in ~/library/application support/minecraft
Delete the entire Minecraft folder.
Next you have to get rid of any Java prefs. So, go to System Preferences and click on Java. When the launcher comes up go to the General Tab, and hit view. Choose resources and delete any temporary file that says http://minecraft.com
Next choose applications, and if Minecraft appears there, delete it.
This should clear the ENTIRE install from your computer!
Side note: While you are in the Java prefs, you might as well click the update tab and make certain you have the latest version of Java.
After this you should be able to make a new clean install.
Source with modifications