Here is what I did:

Look at right side column and click on this:

You can download the new version here.

You then have to click on "Allow" in the right, near-top corner so FF allows the pop-up.

A menu pops up with this inside it:

Then click on "Install Now"

You will then get another pop-up that telss you it will install once you restart FF.

That should do it.

 {Removed third party links}