Need to collect a few videos to study thoroughly

This is the first video on this, and it is good.
I found this one also very helpful.
This guy is talkative 
This British guy shows his way to create the door from the existing wall

Here is the what it look like before. And I will post after I install the new door.

We bought a Kohler brand touchless kitchen faucet a few years ago unfortunately I did not document it properly, at this moment, I found the closest model on youtube. It does not matter and what matters is that it leaks and I need to fix it.

My faucet has two places that one can access,

Upon checking the videos on the Youtube, I found the following few helpful

This video provides the general idea how to access the cartridge. Basically, one need find the little hole on the handle, normally use an Allen wrench (or hex wrench) of 5/64 or 7/64 to loosen the top, then we can open it up and do the following repairs.

This guy also has a good video  on fixing the faucet.

This guy has the Kohler touchless for sure. He shows how to replace the battery. Mine is powered by household electricity so I never worry about replacing the battery.

There are other video like this one, basically they all have similar mechanism. 

Kohler has life time warranty lon their cartridge, but they need receipt (which I have lost) to receive the free part.

Regardless, I have found part diagram, but I need to further select service part for Rival® K-30472. Hopefully I can get the part to proceed with the fixing.