The reccomendedrecommended approach is to choose a relatively quiet time (i.e. minimal log activity) then do the following:
- Backup the log
- Shrink the log file with DBCC SHRINKFILE with TRUNCATEONLY to get it as small as possible
- Run ALTER DATABASE MODIFY FILE to re-size the log to an appropriate size
Appropriate size for the log is of course dependent on your observations of log usage for each database.