Upper Rack Roller replacement GE triton

I need to replace a upper dishrack roller for GE triton (part number WD12X383). I can’t figure out how to get the top rack off the upper rack slide and remove the upper rack rail end cap to relpace roller. Any ideas how to get the end cap off?

Take a look at this post
http://forum.appliancepartspros.com/dishwasher-repair/15506-remove-end-caps-upper-dishwasher-rack.html?highlight=rail+end+caps

That other post was the key to getting the end cap off. The small screwdriver and twisting action worked. Thank you.