phpbb forum affecting MySQL server performance

Hi, This is a very *URGENT* job that I require doing asap. This is a very simple job for those who works close with phpbb forums. My account has been suspended due to my phpbb forum affecting my hosts MySQL server performance. The table "phpbb_users" contains the maximum number of rows which looks like spamming. Your job is to make sure to clear off the junk contents from the database which are not the contents of the website to avoid suspension of the website. Your changes must not affect my phpbb forum and my image gallery software, as well as the static websites. I am currently online now ready to do this project, please have skype ready.