I know there have been posts regarding this, but I`m a bit unclear. With the LOW END NEEDLE, there is the BLUE collar that has the post sticking out of it. That collar appears to be held in place with a grub screw. To remove the BLUE collar, does one simply remove the grub screw and slide the collar off? Do you have to pull the little limiter post out first, or does it just slide off with the BLUE collar? Also, immediately inboard of the BLUE collar there is a METAL collar, also apparently held in place by a grub screw. Should the METAL collar also be removed? Any help is appreciated. Thanks.