01

 The 'Instance Methods' are used on build() object. The methods are specific to versions of apis being used.

 The Documentation is located on 'Supports APIs' page. Go back to the previous from the build() documentation page we left off on.

Or click here, https://googleapis.github.io/google-api-python-client/docs/dyn/youtube_v3.html

Type "Command + F" to find the 'youtube' api 'v3' version 3.

We want the channels() 'Instance Method, click it

02

These are the Instance Methods for build(), we are interested in channels(). https://googleapis.github.io/google-api-python-client/docs/dyn/youtube_v3.html

03

The 'Instance Methods' can contain other ''Instance Methods'. We are interested in the list() 'static method'. Note, that the part paramater is required