After you plug in your adapter, the updater shows two choices via an alert in the upper-right corner of your display: Install and Not Now. Click Install. Follow the on-screen instructions to install the update. When the installation is complete, click the Restart button that appears.

Your MacBook restarts and the Apple logo and progress bar appear. Your Mac then updates the USB-C Multiport Adapter. It takes several minutes for the update to complete.

When the update completes successfully, your Mac restarts into OS X.

Important: Don't turn off your computer or disconnect your adapter during this update.