Change to another group name

[evergrean100]

How do you change group name in a directory to another group name that already exists?

I have a directory with files like this:
-rw-rw-r-- 1 jones oldgroupname 11112 Nov 25 2006 file.pl
-rw-rw-r-- 1 jones oldgroupname 11112 Nov 25 2006 file2.pl

I need the group name to be changed to:
-rw-rw-r-- 1 jones anothergroupname 11112 Nov 25 2006 file.pl
-rw-rw-r-- 1 jones anothergroupname 11112 Nov 25 2006 file2.pl

 

[max1x]

As root do: chown -f user:group filename

chown -f jones:anothergroupname file.pl