The following article details how to remove the PDF password using the website Smallpdf.com.
Step 1: Visit the website https://smallpdf.com/unlock-pdf.
You can select source files from your computer, from Dropbox or from Google Drive. In this example, select the source file from your computer.
Step 2: Click File to select the file from your computer. A dialog box appears selecting the file you want to unlock -> Open .
Step 3: After selecting your file has been uploaded to the Web. Check the box -> Click and Unlock PDF .
Step 4: The file has been unlocked. Here you can download the file to your computer or download Dropbox or Google Driver depending on your purpose. Here I still choose to download the computer to facilitate the work => Click to select Download files now .
During the unlock process, if an error occurs, click Start over . The resulting file is downloaded to the computer with a name distinguished from the source file. And now you just need to open the file without having to enter the password.
Above is the simple, convenient and fastest way when you want to unlock the PDF file.
Good luck!