Why would you add a ground to a component that was built not to have one? Adding an IEC connector as a way to upgrade the power cord isn't reason alone to add a ground to the equation. I have done this simple conversion to an old Sony XBR & a Sony DVD player I liked the subtle video improvement to each, w/o adding a ground connection.
Back in the day,Radio Shack had an awesome tool called
The Nibbler for making the IEC hole. I found this one on Ebay.
Cheers,
Robin