So I was able to do this without killing myself, but sadly the video is still broken. I think I suspect I/O board - perhaps the contrast circuit.
I have another borked I/O board I'll try tomorrow, perhaps it has less damage, but I think the VIAs on it are messed up so might need to transfer them over.
I'll have to also swap the 800k SunRem I/O ROM as this Lisa has one of those.
I used a very long 10" 90' pliers which came in handy:
https://www.amazon.com/gp/product/B00YQ7RWCW/ - I bough this for car work, but it went well here too.
I wasn't able to remove the CRT neck shield off because one of the screws was corroded badly. But I removed all the other screws so was able to push it out enough to get the white doughnut connector out. I used the tips of the pliers at the 9pm and 3pm marks to push it out.
The 8 pin cable from the flyback to the analog board was quite the mofo to get out. The pliers worked there too. This time I was ok with wiggling the connector left/right.
I also soaked a bit of paper towel in distilled vinegar and placed it on top of a corroded part of the stainless steel and within a few minutes it got rid of the haze, I wiped the excess off with water. Have to clean the rest of the case.
So to get to the point, if you have a Lisa that just displays a square white display with diagonal lines, it might not be the analog board.