Yes.
If one of these upgrades is on a character, and I play another upgrade of that type to replace it, does the ability trigger?
[Source: WotC]
Yes. Replacing an upgrade this way causes the old upgrade to be scrapped.
The cards Dismantling Claw,
Reactive Armor and
Personal Targeting Drone say "When this upgrade is scrapped from a character...". Do these effects trigger when the character is KO'd and the upgrade goes to the scrap pile? Do these effects trigger when you replace the upgrade and it goes to the scrap pile?
[Source: WotC]
Yes and yes.
Yes, you can!
If I KO my opponent’s
Battle Master and it has a Dismantling Claw on it, and it scraps my Dismantling Claw, I think my Dismantling Claw would therefore scrap the newly applied Battle Master due to he is now a weapon on my opponents bot. Is that correct?
[Source: WotC]
That is correct.
When a character is KO’d, all upgrades attached to it are scrapped at the same time. This means they can see each other leave the battlefield, so both Dismantling Claw and
Reactive Armor would trigger.