Via a Canadian American extradition warrant that has existed for a loooong time before the arrest, and in such a way that Meng is protected from extradition if an independent Canadian judge doesn't think the case bears weight?
Not quite sure how this is considered overreach. There's a reason that criminals fleeing to places without extradition treaties with the US is a thing.
This isn't the first person Canada has extradited. Italy, China, Netherlands and Mozambique all make an appearance in the list of people worthy enough to also have Wikipedia pages[0].
European countries regularly refuse to extradite people to the US if they think they're at risk from the death penalty there.
America may be large and powerful, but a country asking one of its closest allies to extradite someone isn't an example of that.
[0] https://en.wikipedia.org/wiki/Category:People_extradited_fro...
If that is how the act when they are considering themselves the underdog or developing countries, imagine what they will do when they are full evolved.
Note: Of course US and many other countries aren't Sane either. But the tone used by the Chinese have never been so strong. It is as if they were back to Tsing Dynasty.