If you do not have Google Chrome, then please install it! The steps to remove the password protected PDF using Google Chrome is sooooo easy!
Firsty, open the Google Chrome and just drag your password protected PDF onto it.
There will be a pop up prompt asking for password. Just enter the password.
Once the PDF opened, click on the print icon (CTRL + P). Click on Save.
Save to your local PC. Once done, you can now open the PDF without password.