Open Steam
Go to your Library
Find the game you want to update
Make sure you are online
Check that the game is not set to pause downloads
Steam usually updates games automatically
If an update is available, it will start downloading
Click Downloads in the bottom bar to view update progress
Right-click the game and select Properties if you want to check update settings
Go to Updates in the Properties menu
Set automatic updates if needed
Restart Steam if the update does not begin
Verify the game files if the update fails
Launch the game after the update finishes