Broken rack roller for upper tray

My suggestion is to replace all four rollers at the same time since they are all the same age. Fortunately, four rollers come in each pack you order. You need to remove the end cap on borh metal rack rods which takes a little doing. You cannot just pull the caps off. You need to twist the end cap to free up the little catch at the rear of the end cap. Once the end caps are off, just pull of the old rollers and install the new ones, replace the end caps and you're done.