I figure I would update this thread as I have finally got the sliders installed using the Rivet Nuts FINALLY!
So here are my two take-aways:
1) Do not use a step bit for the holes! Use a Micrometer to measure the Rivet Nuts and get the proper size drill bits. The Rivet Nut has to be snug in the hole to not spin this was my primary issue. So for the replacement 5/8" Rivet Nuts I bought from McMaster Carr it required an 11/16" drill bit that I ordered on Amazon since You can't find that size at Home Depot.
I ended upsizing the DS front leg from a 1/2" Rivet Nut to a 5/8" Rivet Nut since the holes were too big. I would recommend doing this anyway since the DS slider only has two legs and it's just two bolts.
2) The 5/8" Rivet Nuts are a beast and even with the Rivet Nut tool they are tough to install. I would not recommend doing the YouTube Nut & Bolt install for these.
My boss was sympathetic to my Rivet Nut issues so he told me to order the tool in case we need to install Rivet Nuts on the work trucks

But as mentioned above even with the tool my shoulders were toast and even used a ratchet strap to close the arms of the tool. Getting the truck high enough for the tool to fit under the bottom of the frame is a sketchy proposition that had two jack stands under the frame as back-up with the jack.
By far my least fun project and it took me forever and a day partly because we have been doing a house remodel for four months now. And I spent an additional $50 to replace all the Rivet Nuts and bolts I had to cut out. Not to mention the $200 tool that the company now owns.