Instructions
CAUTION: Some updates may require you to restart your Mac. To avoid losing data, please save all of your work before continuing.
2) Click Software Update.
3) Click Update Now.
4) Click Install Now.
NOTE: If the update indicates that a restart of your Mac is required, your Mac may restart without warning after this point.
5) If you are presented with a license agreement, review the agreement. If you agree to the terms, click Agree.
6) Wait for the software update to download.
7) Follow the prompts to restart, if indicated.
Outcome
Continue repeating the steps above until you receive a message indicating that no updates are available.
TIP: We recommend enabling automatic updates to avoid having to manually install updates.