Well you add $2 into the ruser command.
If the level to be removed is specified $2 will be that level, if not then $2 will be the nick and all levels will be removed.
  • !removeauth [level] <nick> <- removes [level]
    !removeauth <nick> <- removes ALL levels
on *:text:!removeauth*:#channel:{

  • if ($ulevel == 11) {
    ruser $$2 $3 6
    if $3 { msg $chan Auth lvl $2 has been removed from $3 }
    else msg # All levels have been removed from $2
    }
}