Insert the Sierra Wireless AirCard 503 PC Express card (or PCMCIA card using the supplied adapter) into the Mac. The device will be detected automatically and presented as a removable drive:

Double click the Installer file:

Click Continue:

Read the license agreement and click Continue:

Select Agree if you accept the terms of the agreement:

Select the drive you want to install the required program files onto and click Continue:

Click Install, you will be warned that the machine will need to be rebooted once the installation is complete:

Click Continue Installation:

Click Restart.

Once rebooted, open the Applications folder. A new icon will be present for the 3G Watcher connection manager:

Double click the icon:

The Watcher software will determine the correct connection settings to use automatically based on the SIM inserted in the device. To initiate a connection to the Internet click the Connect button.

To manually edit or add new connection settings, select the Preferences menu and click on the Profiles tab: