from Platform Nation
Apparently someone leaked the install files for the NXE on the internet and it is now available for all to try out.
Now to install this, it is really simple, all you have to do is download the update files, you can get them here. After you have the file, you just put it on the root of a USB drive, slap that bad boy into your Xbox 360 and turn it on. From there you will be asked if you want to update and now your off and running.
The link to the update file is posted at the Platform Nation link above