https://helpx.adobe.com/acrobat/kb/installing-uninstalling-acrobat-x-mac.html

Plugins are not installed in Firefox but are on system whether on Windows, Linux or Mac OSX.

Acrobat is just fine it's only in the browser where it's wrong, removing acrobat won't help me!!!! :-)

You are asking how you remove it and James gave you the answer.

Note Flash Player (Shockwave Flash) is another plugin, and something you use in Firefox. Again you will notice Firefox does not have an option to remove Flash Player, directly; because it is a plugin, and you need to remove it using the facilities of the Mac's Operating System.

Note instructions for installing and uninstalling

• Use plugins to play audio, video, games and more
  • Install the Flash plugin to view videos, animations and games
  • Use Adobe Reader to view PDF files in Firefox
• Disable or remove Add-ons

First, to be clear, your screenshot shows "Adobe Acrobat - Create PDF" which is an extension. It is completely distinct from the Adobe Acrobat plugin used for viewing PDFs in a browser tab. Since these two kinds of add-ons are very different, and displayed in separate panels of the Add-ons page, please keep this distinction in your mind when reading the various technical steps you find.

Firefox does not display a Remove button for an extension if it was installed into a "shared" location (that is, not in your currently active profile folder). In this case, it is stored under the Adobe Acrobat program folder. On Windows, I could point you to that, but on Mac...

To find the file, you can research the location in a Firefox settings file named extensions.json. Here's a somewhat roundabout way to look in that file:

Access the File

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter/Return

In the first table on the page, click the "Show Folder" button. This should launch a new window listing your settings files.

Scroll down and find extensions.json and make a copy somewhere convenient, such as your Documents folder or Desktop. You can close out of the Finder window after that.

View the File

Back in Firefox, open that copy of extensions.json in Firefox's "Scratchpad" tool as follows. Launch the Scratchpad from the Developer menu, either:

• "3-bar" menu button > Developer > Scratchpad
• (menu bar) Tools > Web Developer > Scratchpad

Use the Open button on the Scratchpad's toolbar to open the backup copy you made of extensions.json and then click the Pretty Print button on the toolbar to re-layout the data in a more readable format.

Then use Find (Ctrl+f Command+f) to search for some part of the name of the unwanted extension, and you should see various information about it. The descriptor gives its location on disk.

(On Windows, the \ in folder paths is doubled in this file due to the way it is processed. When exploring your disk, read \\ as \. Not sure about Mac.)

Note: you don't need to save the changes to the file when you close the Scratchpad unless you want to keep the "pretty" version for future reference.