Export the private key file from the pfx file:
#openssl pkcs12 -in filename.pfx -nocerts -out key.pem

Remove the passphrase from the private key:
#openssl rsa -in key.pem -out server.key

Export the certificate file from the pfx file:
#openssl pkcs12 -in filename.pfx -clcerts -nokeys -out cert.pem