OK, new lens in place.
turns out one can remove just the board with the lens on it, no need to remove the entire assembly from globe as dfhawk did in his video.
Boy those little JST connectors can be a b***h. Got em out easily enuf without too much mangling per Alastair's excellent instructable, but putting them back in turned out to be p.i.t.a. They kept popping out as I tried to push the connector back onto the pins of the mating connector on the board. Finally managed to get them in so they stayed and were not shorting to each other on the back side, that i could tell.
hooked things up and tested before re-assembly. Noticed the lens doesn't fit tightly into the foam ring (neither did the same-sized original) so I wound a rubber band around it couple times
(it's what i could find -- electrical tape woulda worked too) to make sure no light could leak from the (green led) inside around the lens and back off the glass into the sensor. not sure it matters, but can't hurt, i think.
The original lens was slightly offset from the being fully seated into the 14mm circular fitting so i first tried the new lens at approximately the same offset.
Found I was unable to focus at full telephoto (22mm narrow) zoom. Pushed the lens all the way into the holder and could then focus at full 22mm zoom. tradeoff
tho is that I can no longer focus sharply at minimum (6mm) zoom level. Could not find any offset that allowed for focus at both ends of zoom range, but
that's no big deal, as I intend to use it at the further/longer range, so not being able to focus at 6mm is no problem for my needs. ymmv...
Will have to wait till I find my other 2231 for before/after comparison shots, but I'm hoping to use this for ID'ing people's faces @ ~30-40 feet,
replacing a hik 2332 turret with 16mm lens transplant. the Hik is fine during the day, but not great at night without extra IR (not surprising,
as it's LED's were tuned for the original 2.8mm lens). If it works out, I'll swap the lens in my other 2231 as well and replace the
hik 2032 bullet with 25mm lens transplant currently doing face duty in the other direction...