If this helps anyone else doing a driver mirror replacement for their first time, there are 3 additional door panel clips (besides the ones in the 2018 door panel removal procedure) on the 2021 Honda Clarity front driver's door panel that seem to release last (See arrows on the pictures to show where they are).
The top 2 clips can be reached from the top and I used my nylon pry tool to release them. But the bottom one I just pulled out before I figured it out. I just thought I had to pry a little harder. Of course, now there is a slight gap between the handle and door panel where I used my nylon prying tool. I would think you can unclip it from looking up from the bottom of the door.
And, of course, I broke one of the $1.75 plastic clips as well when it fell off the door panel while I was trying to figure it out and I didn't notice it and stepped on it by accident. And don't get me started on those very thin rubber washers on all of the clips that rolled everywhere.
I replaced both the driver's mirror assembly and the skull cap as a unit because I couldn't get the skull cap off the old mirror without breaking it slightly with my nylon pry tools. A couple of hours, a few hundred dollars, and it was done. I used a "Mr. Clean Magic Eraser" and water to clean the other paint off my paint.

The top 2 clips can be reached from the top and I used my nylon pry tool to release them. But the bottom one I just pulled out before I figured it out. I just thought I had to pry a little harder. Of course, now there is a slight gap between the handle and door panel where I used my nylon prying tool. I would think you can unclip it from looking up from the bottom of the door.
And, of course, I broke one of the $1.75 plastic clips as well when it fell off the door panel while I was trying to figure it out and I didn't notice it and stepped on it by accident. And don't get me started on those very thin rubber washers on all of the clips that rolled everywhere.
I replaced both the driver's mirror assembly and the skull cap as a unit because I couldn't get the skull cap off the old mirror without breaking it slightly with my nylon pry tools. A couple of hours, a few hundred dollars, and it was done. I used a "Mr. Clean Magic Eraser" and water to clean the other paint off my paint.

