I don't think those are servicable anymore. The best thing to do is just buy an MONXT-Omni. Remove existing motor and belts. Leave everything else in place. Then mount to OMNI to the top flange of the existing operator and the extension rod to the door. Wire new op. Off you go. If you have large enough sill, you could do the same with an MOVFR. Just make sure the links don't collide with the clutch.
