Wait until no portion of the active log is within that file (DBCC LogInfo). Once that's the case, ALTER DATABASE and drop the file.
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
We walk in the dark places no others will enter
We stand on the bridge and no one may pass