After three plus years, the screen of my Ray was seriously scratched.
I got a replacement one from Aliexpress for 16 USD some time ago and have just found enough time and courage to install it.
I followed this disassembly guide, but with the slight modification suggested by Ιωάννης-Πάρις in the first comment below the video.
All went well though there are bits of glue coming out at the edges here and there :-)
I prolonged the useful life of the device by a year or two, not too bad.