Sony WF-1000 Case Battery Not Charging

WF-1000XM3 is a pair of unwired, earbud-style headphones that charge in a pocket-sized travel case. It has been noticed that the case is no longer charging when plugged in.

The case is not charging and the internal battery within the case needs to be replaced. The battery inside the case can be replaced with a new cell by lightly prying the case open to disengage the plastic locking mechanisms that keep the case together. After removing case's plastic shell, the internals and battery can be seen; the battery can be unsoldered and removed to be placed with a new cell, which must be resoldered to the positive and negative leads.