2005 polaris 330 magnum just got it has been in a barn for last 6 years (Barn Find, HA HA) any how i am cleaning the carb and replacing jets and such my question is the tower where the fuel mixture screw is located is sealed with a brass disc with a hole in the top. How do i correctly remove this disc and is it necessary to reinstall after cleaning the carb? this is my first Polaris ATV and I want to do this right.