How to Unlock PDF Mac?

1: PDFCrack is the best free PDF password recovery tool available, assuming that's what you're after - an actual password "recovery" and not a simple PDF password removal or reset.
Method: PDFCrack would be considered a true PDF password recovery program since it recovers both the user password and owner password from encrypted PDFs. PDFCrack uses a brute-force password recovery method.
Limits: PDFCrack works with PDF files up to version 1.6 with 128-bit RC4 encryption.
2: PDF Unlocker Mac
PDF Unlocker Mac is a easy-to-use PDF Password Remover Mac tool which can help you unlock and decrypt PDF password protections and remove restrictions on printing, editing and copying directly on Mac os x 10.5.8.-10.8.3 Mountain Lion.
3: GuaPDF, sometimes referred to as Guaranteed PDF Decrypter, is a combination PDF password remover/recovery tool. GuaPDF is easy to use and doesn't even require installation.
Method: GuaPDF is primarily a PDF password remover tool for the owner password but can also be used as a PDF password recovery tool for 40-bit encrypted user passwords.
Limits: GuaPDF works with PDF files up to version 1.7 level 3 even with 256-bit AES encryption. However, GuaPDF will only decrypt PDF files at higher levels of version 1.7 if the encryption is at 128-bit AES.
4: PdfCrypt is the Windows command-line version of PDF Password Remover Online. Just specify the input and output PDF and a decrypted PDF file is instantly generated.
Method: PdfCrypt is a password remover tool. PdfCrypt will not find an owner or user password.
Limits: PdfCrypt works with PDF files up to version 1.7 level 8 with 128-bit AES encryption.
5: PDF Unlocker is a Windows installable program that will find the owner password of a PDF file. PDF Unlocker works much like PDFCrack but is instead a native Windows application, making it a bit easier to use though noticeably slower.
Method: PDF Unlocker sounds like it might be a PDF password remover tool but in reality it's a PDF password recovery program since it discovers the actual owner password from an encrypted PDF. PDF Unlocker uses a brute-force password recovery method.
Limits: PDF Unlocker works with PDF files up to version 1.7 level 8 with 128-bit AES encryption.