Sql Server Shrink Log File

Easy with Simple Recovery

DBCC SHRINKFILE ("<FileName>_Log", 1);
GO

otherwise

http://social.technet.microsoft.com/Forums/sqlserver/en-US/0a7a7fc5-d30e-4841-8ed1-84676b575e55/sql-server-2012-how-to-shrink-the-database-transaction-log

USE AdventureWorks2008R2;
GO
-- Truncate the log by changing the database recovery model to SIMPLE.
ALTER DATABASE AdventureWorks2008R2
SET RECOVERY SIMPLE;
GO
-- Shrink the truncated log file to 1 MB.
DBCC SHRINKFILE (AdventureWorks2008R2_Log, 1);
GO
-- Reset the database recovery model.
ALTER DATABASE AdventureWorks2008R2
SET RECOVERY FULL;
GO