You can get the throttle plate out easily, but that is about all you can do.
I found it impossible to get the throttle shaft out, I don't know how the boring out guys do it, and a long search of the web was no help.
I passed my old 68mm TB on to maxchicon to see if he could figure it out, no joy.
( Max is one of those rocket scientist guys )

I do know there is a BIG A** spring in there, so BE CAREFUL !!!!