I tried to soldering it today, but I failed, and my phone barely survived my attempts. Shaky hands seem to be a major obstacle, and I had underestimated how tiny the space on the left side is – you need a really small soldering iron.

I managed to solder only the right side, and I'm not certain it's stably attached to the scraped part – it doesn't appear to be attached at all. And you can laugh at me for the spilled tin all over the place and the almost severed link for the µSD. Picture:
https://imgur.com/7O3VE

I'm leaving it that way until it breaks, and then I'm buying a new phone second hand (or an N9).

My advise: get someone who knows how to solder to do it for you if you can't. And try practising soldering on something else first (didn't help in my case though).

Another note of warning: Be careful when screwing the TORX+ screws, I think I broke something, but I don't know what.

Another useful note: When assembling, slide the monitor up, there's a small part of the metal plate that has to go under the keyboard. It took me a few assembly attempts to figure that out and it isn't mentioned anywhere. If you don't get it right, the bottom side of the monitor sticks up (and if you power up the phone, there's a dark spot on the monitor during sliding).