After market upper steering column bushing (Brussegard?)

[36tudordeluxe]

I've got one of Brussegard's upper steering bushings that fits in the column tube, got many years ago. There are two small set screws at the top of the bushing that I can't get to; does anybody know how this works. Would imagine the set screws are suppose to lock on to the steering shaft but I don't see how to make that happen.