Yes, it is very easy if you take advantage of the fact that those who created it were quite careless. The author of your own link said this: "First, digital document analysis can detect manipulation, but it cannot determine whether the original subject is authentic."
Then, he goes on a wild goose chase regarding how PDF files are created without first examining what that particular PDF file was before it was created. That particular document is not a printed/scanned image that was then converted into a PDF file. It is a clipping mask that was created in Adobe Illustrator, and then output to a PDF file without being flattened into a final image. That is why you are able to deconstruct it back into all of its primary frames for examination. (Without digging out my notes, I seem to recall it had at least four mask layers, and not just two PDF layers as your reference indicated.) From there, you can easily see what components got edited, subtracted, or added from other sources. And, that particular clipping mask is full of surprises.
Without going into further detail, it all boils down to this: In August 1961, they did not have:
1) Typewriters that produced proportional spacing
2) Typewriters that produced kerned fonts
3) Computer word processing and publishing
4) Graphics editing software
5) computer disk/tape digital document storage
The Obama long form birth certificate is as fake as a three-dollar bill.
I have not personally reviewed the birth certificate in a page layout program.
This is what I did decades ago in a page layout program. I created a form layer. This was all lines and boxes. I put labels (First name, Last name, Middle Initial) in a second layer. Printing these two layers results in a blank form. The third layer was for user data (Barack, Hussein, O.). Any similar layering would be proof.