source: http://www.markbrilman.nl/2011/08/howto-convert-a-pfx-to-a-seperate-key-crt-file/
openssl pkcs12 -in [yourfile.pfx] -nocerts -out [keyfile-encrypted.key]
What this command does is extract the private key from the .pfx file. Once entered you need to type in the importpassword of the .pfx file. This is the password that you used to protect your keypair when you created your .pfx file. If you cannot remember it anymore you can just throw your .pfx file away, cause you won’t be able to import it again, anywhere!. Once you entered the import password OpenSSL requests you to type in another password, twice!. This new password will protect your .key file.
Now let’s extract the certificate:
openssl pkcs12 -in [yourfile.pfx] -clcerts -nokeys -out [certificate.crt]