official c3 plugins is very helpful in convert c2 plugins.
the codes are minify. but still understandable.
you can download the "save all resources" plugin from the Chrome Web Store for to download all c3 plugins.
and you can write "c3_runtimeInterface._localRuntime" to the debug console for access the runtime. (type "c3runtime" for c2)
In this way, you can search for c2 values in c3.