While the way Tim illustrates is the correct way to make the changeover, the common way to do it 50 years ago was to cut a hole big enough to accommodate the entire hump and them put a piece of foam rubber over it for an insulator. As for the shift linkage, there is a coupling on the shifter shaft. We took them apart there and removed the shift lever and left the rest of it. It all depends on what you want it to look like.
