Hi Suresh,
Check if the database recovery model is set to Full.
If it is, change it to Simple and then Shrink the database files.
That should reduce the size.
There are a few SAP Notes about this topic:
Note 1224089 - How to shrink a MSSQL Server 2005 / 2008 Database?
Note 1651592 - Unable to reduce the size of the Log file
Note 2078341 - How to Maintain Database & Log File Settings for SAP Business One
Kind Regards,
Nick Lakasas