I called Audeze and the person asked for serial number and then sent me a invoice and done deal. I bought the grills from Audeze for $40. No funny business to deal with. My XC I got from HeadAmp so no issue not buying directly from Audeze. In my case the headphone did 180 on sound. The caps and grills come with the dampening installed. Easy swap.
OK, thanks. When I saw your post I started googling and found this guy on eBay who sells a "kit" that will let you turn Audeze open backs into closed: https://www.ebay.com/itm/124419847484 I ordered a set as I have always wanted to use my LCD-X at the office.