Open the PDF in a PDF editor that supports form fields and signatures
Locate the signed signature field
If the signature is a digital signature, verify whether the document allows removal or clearing
Right-click the signature field and choose Remove, Clear, or Delete if available
If the signature is part of a form, delete the signature field from the form editor
If the signature is an image or annotation, select it and delete it
Save the PDF as a new file
If the PDF is locked or signed with certificate protection, create an unsigned copy only if you have permission
If removal is not allowed, contact the document owner or signer for an updated unsigned version