And you only need the serial port for a very short time, just long enough to type: /mnt/us/jb.sh
So you will find posts here by people (also soldering iron challenged) that have held the leads in-place with tape.
Check my "KT2 Exposed" thread for some close-up photos to see what you will have to deal with - - those are **tiny** connection points.
- - - -
I don't think you will find any write-up posted here (yet) of a PW-3 teardown . . .
I know we don't have a wiki index page for the PW3 prefix (yet), because I haven't done it.
But your favorite web-search engine should be able to find PW-3 teardowns by now.