Evince is the default PDF file viewer that comes with Ubuntu. You can use it to remove a password from a PDF file as long as you know the password. It’s a graphical tool, but we will run it from the command line. To run Evince, type the following command at the prompt and press Enter.
Replace the full path and filename for your PDF file.
NOTE: You may see the following error message, but the file will open anyway.
Evince displays a dialog box asking for the user password to open the PDF file. Enter the password in the edit box and select how long you want Evince to remember the password. Click “Unlock Document”.
When the PDF file opens, select “Print” from the “File” menu.
On the “Print” dialog box, select “Print to File”. If you want to change the filename or the location where it’s saved, click the button next to “File” showing the path and filename.
On the “Select a filename” dialog box, navigate to the location where you want to save the unprotected PDF file and enter a name for the file in the Name field. Click “Select”.
The new path and filename displays on the “File” button. Accept the default settings for the other options and click “Print”.
The unprotected PDF file is saved to the location you chose.
Double-click on the file to open it again in Evince. Notice that you are not asked for the password.
Remember, to remove a password from a PDF file using these tools you must know the password.