First, it is important to note that a Code Signing Certificate can only be generated and exported from Firefox. The steps for exporting your code signing certificate and private key in Firefox are as follows:
- Click the "Open" menu
- Select "Options"
- Click on "Advanced" or "Encryption"
- Under the certificate tab, select "View Certificates"
- Under Your Certificates, click your certificate name
- Once highlighted, select "back up all" and enter in your passphrase