We have a leaky sink faucet in the Back Bathroom. By turning off the water supply for the cold and then the hot water under the sink, we were able to identify that it was the hot water faucet leaking.
First we needed to get a replacement cartridge for the faucet. It is an American Standard Amarilis Iris faucets, so we found a replacement cartridge for that
The first problem is removing the handle and escutcheon for the faucet.
Normally there is a small set screw that holds the handle on, but I could not find any. Going back and looking at the installation instructions, it suggests that it is under the ring that is at the top of the escutcheon. And sure enough, with some work, I was able to pry it up revealing a little groove under the ring, with a set screw.
Once the set screw is backed out, the handle comes off and then the escutcheon, leaving only the mechanism.
That is held in place with a large hex nut. Removing that allows us to replace the cartridge.
And then we reverse everything to put it all back together.
Testing it, we have hot water and no leaks.