I've got the most recent iteration of the WO GT81 (link) and just received the WO 6AII Field Flattener (link) in the mail. The sales page for the FF shows an image of the compression ring removed from the focuser tube and the FF taking its place (w/ M63 threading). I've tried unscrewing the ring with no luck. There also seems to be three small hex screws holding the compression ring in place. I've tried unscrewing them, but none of my hex keys fit. However, I'm not sure the screws are holding the ring in place.
Has anyone else struggled with this who can maybe lend me some advice? Pics of the compression ring can be found here: https://photos.app.g...JjWiRK5cFqUiXj9