How to replace keys

The newer butterfly keys are a real bear! I have yet to fix a key without breaking the cap! Here’s a good source 2019 keyboard parts

Frankly, I would see if Apple will replace the keyboard as the design is just not serviceable.

I had some sticky keys after a minor spill, I took the logic board out, cleaned it etc, and while it was out, poured demineralised water (tilted away from and avoiding the battery connections), let it dry, then did the same with isopropyl alcohol. Left in a warm room to dry for a few days before re-inserting logic board. Sticky keyboard, including a key that had already been giving me issues prior to the spill, went away. Hope this helps someone!