In case you have a wildcard PFX certificate and you need a PEM and your private KEY:
A *.pfx certificate is a PKCS#12 format and includes both the certificate and the private key.
openssl pkcs12 -in ABC.pfx -nocerts -out privatekey.pem -nodes
2. Export the certificate
openssl pkcs12 -in ABC.pfx -nokeys -out cert.pem
3. Remove the passphrase from the private key
openssl rsa -in privatekey.pem -out server.key 