How do I change the gidNumber of a existing group from Command line?
The attribute is called gidNumber.
I'm guessing "dsmod" is your ticket. Not sure exactly how you have your gidNumber attribute setup, but Microsoft's TechNet has everything you can do using this command to modify group attributes here: http://technet.microsoft.com/en-us/library/cc755470%28v=ws.10%29.aspx#BKMK_3
Hope that helps.
I'm guessing "dsmod" is your ticket. Not sure exactly how you have your gidNumber attribute setup, but Microsoft's TechNet has everything you can do using this command to modify group attributes here: http://technet.microsoft.com/en-us/library/cc755470%28v=ws.10%29.aspx#BKMK_3
Hope that helps.