CAUTION! I completed this process to replace the battery on mine, and there is one IMPORTANT step that should be on this guide. Before removing the battery, a plastic card should be inserted between the battery contacts and the underside of the mainboard to isolate the battery from the contacts on the underside of the mainboard. When I was working the adhesive on the battery contacts from the chassis, the connections crossed and shorted something and burned out the IT8528VG chip. I contacted a repair shop regarding replacement of this part and they said it requires a hot air station to remove and micro soldering to replace. They said they see this common error when repairing. Now my Surface is a paperweight. Please add this crucial step to these instructions.
It is very frustrating to have performed this long, difficult process perfectly, with an intact Surface screen at the end, only to have irreparably destroyed it because of one important missing step.