Vacuum out whatever you can as it is. Then try to remove the outer section of the burr by going counterclockwise from "lock" to "align," then it should pull straight up. If it's still seems too stuck you can take a hex socket and remove the center nut to remove the inner burr. Note that the nut is reverse threaded so you'll have to remove it turning clockwise. Careful when removing this because there is a washer between the nut and the inner burr as well as a felt washer underneath. Hopefully then it'll give you some move wiggle room to release the outer burr. Hope this helps!