How to: Remove a Password From a PDF File | ITechBrand.com
Here we can see, "How to Remove a Password From a PDF File"

Some PDFs are password-protected, requiring you to input the password each time you see the document. If you're keeping the PDF in a secure location, you can remove the password to save yourself some time.

We'll go through two approaches here: The official way, which requires Adobe Acrobat, and a convenient trick that works in all operating systems using applications you already have.