In depth update guide

There may already be one, but I can only see one for 2009 which I can not seem to understand greatly.

I am looking to update the game manually cars, tracks, grid cars, helmets etc

Load them all in piece by piece rather than using a mod so I can make it how I want it.

There is still a fair bit I don't understand in regards to installation

So a really in depth guide would be great no matter what season I install