The download will be around six gigabytes in size, and will continue to pick up data so long as the game launcher is running. You can always check the progress of your download by clicking the "Info" button at the top of the launcher, then selecting "Connection Information" from the drop-down menu. If you wish to complete the update later, simply click the "Play" button at any point to pause the download and run StarCraft II, or close the launcher. Unlike some of our other games, no background downloading will occur while StarCraft II is running. Data will resume downloading the next time you run the launcher.
That’s all there is to it! Stay tuned over the coming weeks for more information about the impending patch. Until then, we'll see you on Battle.net.