Modifying individual user's permissions
 

I currently have a certain usergroup (let's call it "Usergroup X" for reference purposes) consisting of about 120 users. Each of these users can view threads, post, and use the PM function.

However, we would like to edit the permissions of one particular individual within "Usergroup X" so that he cannot post in threads or PM.

Is there a way to do this without creating an entirely new usergroup with new permissions and then adding the individual to that usergroup?

Any help is appreciated.

Thanks. :)