It is good if you backed up the LOG file also when we take the full backup of the database.

If you are not backed up the .LDF file or LOG  then it will become huge and occupy the large number of space, if you need to clean up the transaction log. Follow the following steps and clean your LOG size.

1)  first take log backup

BACKUP LOG MYDB TO DISK='d:\TEMP.bak' with init

2) Shrink your Database.

USE MYDB GO

DBCC SHRINKFILE ('MYDB _log', EMPTYFILE);

GO

From GUI mode: Rclick  DB ==> Task ==> Shirinks ==> Database ==> specify size and press OK


3) Now see your log and file size.

SELECT name AS [FName] , file_id, physical_name AS [Phy.Name],

size/128 AS [SizeInMB],

size/128.0 - CAST(FILEPROPERTY(name, 'Used') AS int)/128.0

AS [Available Space In MB]

FROM sys.database_files;

MSDN:
You can reduce the default size of an empty file by using DBCC SHRINKFILE target_size. For example, if you create a 5-MB file and then shrink the file to 3 MB while the file is still empty, the default file size is set to 3 MB. This applies only to empty files that have never contained data.