Hello!
It is technically possible to remove the clutch cover on the Retina MacBook Pros but it is a difficult repair, as the clutch end caps are adhered to the display a bit and have small plastic clips that often bend or break.
On top of that, sourcing a replacement clutch cover would likely require eBay or some other method as I don't see the part listed as a replacement part on iFixit.
To the point, you'd first need to remove the display;
[guide|23392]
After that, you'd need a Spudger using the point end to lightly remove the two plastic end caps on either side of the clutch.. This is the hard part as they often break or bend and if they do, they will not sit correctly most times when you attempt to put them back on. (It should be noted though that the clearance on the top case and these pieces is tight, and some people don't mind the clearance actually helping hold the piece on)
Then holding the display with the apple logo towards you and the display pointing away from you (up side down so the clutch cover is at the top), you can carefully slide the clutch to the right, similar to any Non Retina MacBook pro and remove it carefully once the clips are disengaged, This takes some very careful work. Reverse to put the new clutch on, and carefully seat the end caps into their proper spot, then reinstall the display!