You will need to extract that into .pem files for the key and certificate. Here are the commands to execute using openssl command line client:
To export the private key without a passphrase or password.
Type: openssl pkcs12 -in filename.pfx -nocerts -nodes -out key.pem
To export the Certificate
Type: openssl pkcs12 -in filename.pfx -clcerts -nokeys -out cert.pem
Once you have these files you can follow our standard instructions https://helpdesk.nervepoint.com/entries/22083661-upload-an-ssl-certificate skipping the first step as you already have a key so do not need to generate a CSR or new key.