Step1: Open the SQL Server Management Studio by choosing Start > Programs > Microsoft SQL Server 2008 > SQL Server Management Studio.
Step2: right-click on Database and open new sql query and execute following query to shrink Database log file to 20MB
USE [DB_NAME
GO
ALTER DATABASE [DB_NAME] SET RECOVERY SIMPLE WITH NO_WAIT
dbcc shrinkfile(DB_Log_File_Name,20)
ALTER DATABASE [DB_NAME] SET RECOVERY FULL WITH NO_WAIT
GO
Note: Above colored texts are variable
USE [servicedesk]
GO
ALTER DATABASE [servicedesk] SET RECOVERY SIMPLE WITH NO_WAIT
dbcc shrinkfile(servicedesk_log,20)
ALTER DATABASE [servicedesk] SET RECOVERY FULL WITH NO_WAIT
GO
