[WindowsCentral.com]

Can you upgrade the storage in a Surface Book?
Updated May 29, 2017: We've refreshed this list to ensure you're still getting the cheapest and easiest way to expand your Surface Book's storage.
The Microsoft Surface Book is a very powerful laptop with a 2-in-1 design, a touch display with a unique aspect ratio, and a high price.
One of the best ways to lower the initial cost of a Surface Book is to dial back the hardware inside, namely the solid-state drive. You can save hundreds of dollars by opting for a 256GB storage option rather than a 1TB option.
Even if you did opt for a big 1TB solid-state drive, the reality of media today is that it will eventually fill up. In either case, you're probably wondering how to get a bigger drive when the Surface Book doesn't have upgradeable hardware.

Full story from the WindowsCentral blog...