Open the PDF in a PDF editor that has permission to remove security
Enter the password when prompted
Go to File or Document Properties
Open the Security tab
Select No Security or Remove Password
Save the PDF as a new file
If the PDF is owner-protected, use the owner password to unlock security settings
If you only have the open password, you cannot remove it without the correct password
In Adobe Acrobat, use File > Properties > Security > Security Method > No Security
In Microsoft Edge or Chrome, print the PDF to a new PDF file if allowed
In macOS Preview, open the PDF, enter the password, then export or save a copy without security if permitted