RAR Password in 5 -15 minutes? Do you believe that?

Of course you can bypass the password check by cracking WinRAR. But this will not help you, since the data is encrypted. Without the correct password (or password-hash) you will never be able to decrypt the data in a way it could be decompressed. You should better read a bit about the basics of cryptography, if you don't understand how this works.

And when I read the "hints" the author gave you, I was 100% sure that it's a fake. WinRAR doesn't have anything to do with PGP SFX and nothing can be done by modifying the file headers.