The Plumbing Wizard
The Moen Renzo faucet CA87316
This was a replacement for an older one, let's take a look.
The mounting cap can be installed either of two ways. This one was installed this way making it hard to use anything but the supplied Moen wrench. It was solidly on there, and the wrench wasn't having any.
I took my pliers and ripped off the flange in my way. I tried drilling out the nut but Moen made theirs out of Superman steel.
Now I can't remember whether the tool worked at this point or did I use my small adjustable spanner. That's what we called a crescent wrench in the bicycle shop with the owners from England.
It came off.
The new Moen Renzo faucet had a flat plate going up against the sink. I like that idea better.