How can I completely remove Apple's Java 6 and make Oracle's Java 7 default for everything?
Download and install the latest Java Development Kit (JDK) from Oracle, which will place it in /Library/Java/JavaVirtualMachines/jdk1.7.0_11.jdk (or whatever the latest version is). Now, start Terminal.app, and enter the following commands:


cd /System/Library/Java/JavaVirtualMachines (change to the proper directory)
sudo mv 1.6.0.jdk backup.1.6.0.jdk (keep the old JDK around, just in case - you will need to have an administrator password to do this)
sudo ln -s /Library/Java/JavaVirtualMachines/jdk1.7.0_11.jdk 1.6.0.jdk (link your new JDK installation to where applications expect the old one to be)


Keep in mind that with any further jdk updates, you'll need to update the symlink to the new directory: 

sudo rm /System/Library/Java/JavaVirtualMachines/1.6.0.jdk &amp;&amp; sudo ln -s /Library/Java/JavaVirtualMachines/new_jdk_version /System/Library/Java/JavaVirtualMachines/1.6.0.jdk