You will get your phone in the original package, unopened. I think they will help you if they are very nice. But, Google has been working a lot to make sure you transition very easy from any phone to Pixel 2 XL thus there are a couple things that make this process super easy and intuitive.
1. They include a cable, so that you can connect your old phone with pixel
2. When starting the phone first time, you will have the chance to copy everything from your old phone and it will guide you to do that.
3. The support from Settings is super fast & ready to help. Very nice guys over there. The called me back in ~10 sec and I waited on line for about 20 seconds more. Then, a very nice guy was ready to help me with anything regarding my Pixel 2 XL. (that's a premium support I'd say).
As a conclusion, you can do it yourself without any friction, and if you won't be able to, then support will 100% help with it.