It is not impossible to repair a tablet like the Surface Pro 3. But you are going to have a real challenge replacing its battery and anything other than its SSD. The folks at iFixIt have published their teardown report for the Microsoft Surface Pro 3 and given it a repairability score of 1 out of 10. While you can replace the hard drive, the battery, display, and other parts are not easy to repair.
The battery is not soldered to the motherboard, but very strong adhesive makes removal and replacement a hazardous chore.
Many modern, thin laptops are also hard to repair. But it would be nice to be able to upgrade expensive tablets like this. Unfortunately, that’s not what manufacturers are offering at this time.[Source]