February 16, 2012, 4:11 PM — Here's how to install the OS X Mountain Lion Messages beta software on your Mac. Before installing Messages, make sure that you have closed iChat on your Mac. Messages will replace the iChat software.
1. Download the Messages beta software file from the Messages beta page.
2. After the software has downloaded, double click the MessagesBeta.pkg file to begin your install.
3. The installer menu will appear, click the Continue button when you see it.
4. Click the Continue button again when you see the Read Me message.
5. Click Continue a third time when you see the License message, then click the Agree button.
6. Click the Install button when the Installation Type message appears (you can also opt to change the default install location if you wish).
7. Type in your password when the password confirmation appears, then click the Install Software button.
8. A message will appear informing you that you will have to restart your Mac after the install finishes. Click the Continue Installation button or Cancel if you prefer not to continue the install right now.
9. The install will begin and when it is complete you will see the Summary message.
10. Click the Restart button to restart your Mac after the install finishes.
Messages replaces iChat and offers the following cool, new features:
"Send unlimited iMessages to any Mac, iPad, iPhone, or iPod touch.*
Start an iMessage conversation on your Mac and continue it on your iPad, iPhone, or iPod touch.
Send photos, videos, attachments, contacts, locations, and more.
Launch a FaceTime video call and bring the conversation face-to-face.
Messages supports iMessage, AIM, Yahoo!, Google Talk, and Jabber accounts."
