Old roller wheels were starting to stick due to cracking

1. I pulled off the plastic end caps to the top rack that allows the roller wheels to be pulled out of the aluminum rails. You need to push in the raised edge of the plastic caps so they clear the rail slot in order to remove them. This takes a little bit of finger pressure or you can use a flat-edge screw driver to pop them out.
2. Once this procedure is completed, you simply remove the rack and rollers from both rails and remove the old roller wheels and replace them with the new ones.
3. I used a phillips-head screw driver to tighten up the rail wheels before re-installing the top rack into the rails and then re-inserted the end caps. Pliers are handy to help get the end caps back into the rail slots.
4. I finally used a silcon spray on all of the rolling parts of the top tray assembly for lubrication.