[ForceHSS]

As I said in my first post you need the full ip if all spammers IPs were the same then you could but if doing it from a query it will cause problems

UPDATE `user` SET `usergroupid`='8', `ipaddress`='FULL IP HERE' WHERE (`userid`='2')
this will move them from group 2 to 8 with x ip
then you could use the prune option to delete all in that group

is only the first 3 numbers of the ip the same and how many spammers and do they have posts. If the forum you are helping I can give you a plugin that will delete all there posts and delete the accounts