As we mention in TIP 10 to set database user as Single user now to make this available again for all the user or multi user we need to do following
ALTER DATABASE FriendsDB
SET MULTI_USER
WITH NO_WAIT;
GO
Here when we run above command FriendsDB again changed to MULTI USER.
Here NO_WAIT means not wait for statement with immediate response.
When we run this command database again change to multi user as shown in below fig
Enjoy !!!