Good Resources to replace WF1000 XM4 Batteries
Today I replaced the batteries on my Sony XM4 earbuds. Here are some resources I recommend if you plan to change the batteries on yours.
Amazon replacement parts:

Not an affiliate link. I do not profit if you get this item. This specific item has genuine ZeniPower batteries unlike other listings which use knock-off parts.
Recommended tools:
1) A hair dryer
2) A hand clamp
A hand clamp makes it super easy to open up the earbuds without risking cutting yourself with a razor blade, or damaging the case with a screw driver.