ReadyNV: Can´t get out the Tray...

I too have had this problem, but luckily I was eventually able to remove both disks from my ReadyNas. I stripped the latches off of the tray, but unfortunately broke one of them when I was trying to release the mechanism with a paper clip - you have to be careful, as the actual latch clip itself is made of quite flimsy plastic. Assuming you can get the trays out, you should try lubricating the mechanism with silicone spray first and then work on the sliding 'tabs' to the left and right hand side of the latch as viewed from the 'inside' (i.e. the face of the latch that is normally against the metal tray), rather than on the latch clip itself.
Next day, for my second tray, I bought some silicone and sprayed it all over the latch mechanism from the inside, and on the button from the outside - it now works perfectly.
My ReadyNAS is 6 months out of it's 3-year hardware warranty. So I e-mailed Netgear to ask how much it would be to buy a new tray. I mentioned in the e-mail that I had looked up the forums and found this was a well-documented flaw with ReadyNAS latches. To my surprise, Netgear Support immediately offered to replace the broken tray completely free of charge, without so much as a quibble. That's what I call service !