I was going to add this to my stereo install post....still have to do that....
First pull the door panel off.
Then there is a threaded plastic ring that holds the speaker to the panel, unscrew that.
Remove the tweeter from door panel.
Using a small tool, just pull on the metal grate that is on top of the speaker. I used the hook tool in the picture below.
Once I removed the cover, I used a drill to drill all the way around the speaker, then I used a Dremel to cut between the holes and remove the speaker, leaving the frame left to install the new Focal tweeter in it: