8.75 suregrip gear swap questions

I'm guessing its not to hard of a job because an axle place charged me 65 buck to take a sure grip unit and install it into a 3:55 pig I had. He did all the back lash and whatever else needed done. For that price I figured I'd let the pro do it. This was like 2 weeks ago in Michigan. The place is an old place, with an old guy thats been doing it for 30 years. My favorite kind of place to get work done!