Often you need to restore a DB or take oit offline only to find out the process aborts due to active connected sessions to the DB. Here is a quick sript that will kill all active sessions to the DB.
USE [master];
DECLARE @kill varchar(8000) = '';
SELECT @kill = @kill + 'kill ' + CONVERT(varchar(5), session_id) + ';'
FROM sys.dm_exec_sessions
WHERE database_id = db_id('myDataBase')
EXEC(@kill);