1. Convert .ppk to .pem with putty
  2. Install putty on mac
    sudo port install putty
    or
    brew install putty
  3. Generate .ppk to .pem
    puttygen privatekey.ppk -O private-openssh -o privatekey.pem
  4. Use privatekey.pem root server
    ssh -i privatekey.pem [email protected]