I have my speedo adapter out on the bench and figured it would be a good time to replace the O-ring and seal; however, the seal is buried inside the adapter and it too big to be replaced in the usual fashion. It appears the adapter is a 2-piece unit, with a smaller part--with the threads for the angle drive--inside the 'barrel.' It should come apart, but for a small pin that holds the parts together (see attached photo). Anybody know how to separate the two; hopefully, so they can be rejoined?