If I say legally, then you can't because breaking someone's privacy is not good but if you are the owner of the pdf and you forget the passward then I suggest you. Go to any online pdf passward remover site like PDFfiller.com - A Free Solution to all your PDF Problems or iLovePDF | Online PDF tools for PDF lovers, here you can remove some weak and medium passward protected pdf.If the passward is too strong then those wil not be able. Thank you, follow me for more tips and tricks
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