Start by backing the log up more frequently. See the article I referenced about how often and why you back logs up. If you don't need to back the logs up, then consider simple recovery model
After a log backup, you can just shrink the log. Use the UI if you want. Shrink to a sensible size, not 0. Maybe half the size of the DB.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability