I bought glides from ODM. They did not stock them but ordered them for me. If I remember correctly, they were $35+/-per pair, two years ago.
Slide the pantry out. Then put some kind of brace tight beneath it and have someone balance it while you remove the screws. Set the cabinet out of the way. Remove the rest of the screws holding the old glides inside the cabinet. Install the new glides and cabinet in reverse order.
2014 Silverado 1500 5.3L maximum trailering package (yes, I'm towing the 34')