The below syntax will allow you to shrink a SQL Server Database Data File and Transaction Log File
-- Truncate the log
BACKUP LOG biztalkdtadb WITH TRUNCATE_ONLY
-- Shrink Log File
dbcc shrinkdatabase (BizTalkDTADb, 10)
- Shrink Data File
dbcc shrinkdatabase (BizTalkDTADb_log, 10)