Unlock locked pdf file

i have a pdf file and i cant print it because its locked how can i unlock it?
i google it nad find some sites
http://www.unlock-pdf.com/
http://www.pdfunlock.com/
http://www.webisee.com/2008/08/03/unlock-protected-pdf-select-edit-print-best-ways/
are they scam
Answer #1
I use the first site you posted and it’s ok.
Answer #2
PDF Password Remover v3.12
http://www.verypdf.com/pwdremover/
http://www.~Disallowed~/file/2132434744