Download all of the files included here then follow the blog post for steps. See Examples in PowerShell for command line options.
Add your own Root Certificate to the media and name it root.cer
NOTE: I found that my password contained special characters that caused winpeshl.exe to fail to pass the creds properly. I moved the creds into the PowerShell script instead of passing them in the command line inside the winpeshl.ini file.