Use any thin copper wire (
as instructed,
as big as that lines). Check twice the temperature of the soldering tip. Under microscope, it would need 0.5 second to melt and solder the wire on that line.
In our lab/service center, we can rebuild that 5 tracks in less then a minute. But with min 10 min preparation, which is most important.
So, good luck!
Later edit
If you were able to "carefully" scratch out that layer, you have the ability to rebuild that lines.