It looks like you're going to have to reconnect a couple of traces, but if you've got some magnet wire and a fine tipped iron you should be good to go. You probably don't need that bit on the left, it doesn't look important.
When I worked in cell phone repair, someone brought in a cell phone in similar condition and asked a similar question, all while seeming quite sincere.
At least they were honest; they explained it had fallen out of their pocket while mowing and gotten entangled in the mower blades. Not sure how they expected us to affect repairs, though. We declined as politely as we could and directed them to where they could buy a replacement.
Which guide did you follow? I have some experience in motherboard trimming, but this one doesn't make sense to me. Cutting through the northbridge seems unusual and very hard to get working.
Did you try throwing it in the oven at it's highest possible temperature? Gotta reflow that solder and the board will magically come back together in one piece!