What an unluckly day! After breakfast, I accidentally spilled over half
a cup of water, and some of it went onto my MacBook. I immediately
grabbed some tissues and tried my best to reduce the chance of the water
continuing to seep inside. After drying the surface, I wanted to tear
down the MacBook and clean the internals if necessary.

I already had a pentalobe screwdriver, but I still couldn't open the
back lid because I didn't have the proper suction tool. To prevent
further damage, I gave up disassembling the device and tried to make an
appointment with the Genius Bar. Unfortunately, the earliest appointment
was 3 days away. I couldn't wait that long, and the device probably
couldn't either.

I continued using tissues to absorb water from the gaps between the
keys. Then I realized: why not remove the keycaps from the keyboard? So
I removed around 13 of them. There actually wasn't much water under the
keys, and after checking that everything was still working properly, I
finally felt relieved.

But then another problem came up.

I thought removing and reinstalling keycaps would be easy and
intuitive—just pull them out and push them back in. I was completely
wrong. The keys got stuck and would not pop back up. After serveral
failed attempts, I checked YouTube and started doing some research.

It turned out to be a scissor-switch keyboard, and there is actually a
proper way to remove and install keycaps without damaging them. To
remove a keycap, you have to press the top of the key with your finger,
then use a thin hard plastic tool or paper card to gently lift the key
from the bottom gap. Once you hear a clicking sound, slide the keycap
downward and it should come off safely.

To install the keycap, you reverse the process. First slide it
upward from the bottom, then press the bottom-left and bottom-right
corners until you hear another clicking sound. The key should work
normally again afterward. I recommend watching some YouTube videos
because they explain the process much more clearly step by step.

While reinstalling the keys, I discovered that some of them had already
been permenantly damaged by my earlier naive attempts. There are two
tiny plastic claws on the back of each keycap, and they break very
easily if the keys is installed/removed incorrectly.

In the end, I had to order a replacement set of keycaps from Taobao,
which cost me around 35 CNY. I am not sure whether the quality will be
as good as the original ones, and I still need to wait two days for the
package to arrive. Hopefully everything turns out fine.

There was also an intersting finding. One of the damaged key was the
Delete key. I didn't know that the shortcut ctrl+h has the same function
as the Delete key on macOS. Since I had already remapped the Caps Lock
to Control earlier, using ctrl+h to delete a character actually feels
much more convenient than reaching for the "far away" Delete key, I may
start using this shortcut instead.

Apple also has an article listing many useful keyboard shortcuts:

Mac keyboard shortcuts
https://support.apple.com/en-us/102650