How to drop a redo logfile group and redo logfile group members - syntax

alter database drop logfile group 4;

The drop statement will be confirmed by an entry in the database's alert log.

Don't forget to physically remove the file from disk afterwards.

You can also drop individual Group members:

alter database drop logfile member '/u03/oradata/proddb01/red04a.log';

Pay attention to the restrictions when dropping redo log groups and redo log members!

A good Query for redo log file information can be found here