I didn't know there user guides for phones!
The only thing I saw was a tear down. Which was pretty positive. The only issues were that the USB port is soldered onto the motherboard so would be a PITA to replace and the screen would be easier to replace if you had a screen that already had the backing plastic bracket attached - apparently, LG sold a similar combination for the original N5. Otherwise, it looked really easy to repair. The only glue was holding the battery in place.