Can anyone tell me if I can discard my waste disposal unit from the kitchen sink and fit normal waste pipes to the trap without having to get and fit a new sink unit? I've removed the unit to have a look and cannot see how on earth the bit that is attached to the sink (to which the unit itself is then attached underneath) is removed. There appears to be no screws or threads and it is as if the thing has been cemented in place. Any help would be much appreciated. Cheers