Don't worry about doing all that manually, I was very thankful to find a Photoshop action that does the job of inverting and adjusting the color levels to remove the orange mask.
I got it from
here to credit him. Fortunately I saved it because it looks like he removed them.
Here's a link to my Drive, which has the action.
HERE
It does a better job than I was able to manually and only takes a second or two. You'll still have to color correct but it makes the process much less painful.