How to Enable Java Applet Plug-in Using Mac OSX 10.7 Lion
How to Enable Java Applet Plug-in Using Mac OSX 10.7 Lion & 10.8 Mountain Lion
Step 1:
Open your web browser and go to www.java.com. (or just click the link)
Step 2:
Click on the Free Java Download button.
Step 3:
Click on the Agree and Start Free Download button.
Step 4:
When the download is completed you will need to double click the installation file from the download window. The file will be named something similar to the screenshot below.
Step 5:
When the installation file opens, double click on the Java installation package icon.