A few notes in case anyone else ends up needing to do this
Due to carelessness on my part, my G7 X took to a head-height fall to concrete. The camera was somewhat precariously balanced, and fell when the lens retracted for power off at the end of the script. Not sure if it was powered off by the time it hit.
Only significant damage was a cracked LCD panel, which still worked. Lens extending / zoom seem a bit noisier too.
I found a cheap replacement panel on amazon
and successfully replaced it following this ifixit guide
plus what's in the comment.
Initially, I didn't fully connect the PCB -> display ribbon cable. In this case, the camera boots (including CHDK, based on LED flashes) and shuts down with an assert
ASSERT!! TouchPanelDriver_TX08D185HM0AAP Line 1874
Task name: TouchPanel
After getting the panel fully connected, the replacement seems completely fine.