[font="Verdana"]There are couple of ways to do it.

1. Textbook Way- sp_cycle_errorlog - Closes the current error log file and cycles the error log extension numbers just like a server restart. The new error log contains version and copyright information and a line indicating that the new log has been created.

Ref.

http://msdn.microsoft.com/en-us/library/ms182512.aspx

2. Restart the SQL Services

3. Stop the Service - Rename The File - Restart the Service.

Enjoy SQL'ing[/font]