Hexo: How to update hexo ?

[NanerLee]

I want update hexo from 3.2.2 to 3.3.0.
But I didn't find anything about how to do it in doc and wiki.
I search it in google. it seems to run

npm update -g 

But after this, hexo --version is still 3.2.2 ?

[NanerLee]

sorry, I find the solution.
only to run

npm update

in my the hexo blog folder.