Fair enough. I haven't seen any of the 10%, but I'm sure they're out there. As an alternative to saying "go find info", how's this: https://www.youtube.com/watch?v=3KDiecphUk8 ?
I just gave it a quick skip through, but the guy seems to know the correct approach.
If someone on YouTube is soldering directly to terminals, in any form, they're badly wrong and I wouldn't trust the rest of their judgement.
I'm not going to evaluate someone's YouTube video on battery repair, sorry. There's no way I can "skip through it" and have any sense of what they're doing, and I generally try to avoid YouTube as a source of information. You'll find far better material on Endless Sphere, though there are plenty of dangerous ideas there.
I just gave it a quick skip through, but the guy seems to know the correct approach.