Was much easier than I thought it would be. I did this a while back, but Pez's post reminded me I still had the photos.
I bought these from the local bicycle shop for 2 bucks each, but next time I'll order online.
These are metric so I couldn't use any bolts I had on hand, but a couple bucks later from Home Depot and I was in business.
Bike shop said to use a screwdriver & hammer to get the nut started into the tube
But I saw no reason to switch to the extention as they explained, so I just kept going with the screwdriver
And we're seated.
Edit to add --- Make sure you don't drive the star nut too deep into the tube.
If you do, the factory length bolts won't reach the threaded portion of the star nut.
Just a quick shot of black paint to cover the exposed metal and these tubes are back in action.