Steam Version - How do I apply data/graphics files?

For the first time ever I have had to purchase FM(15) via Steam as I now live in Russia and in the shops I can only buy a cheaper Russian language version of the game. Every year for the last 4 years I have downloaded the graphics packs and used them with no problem. I have gone to Steam's preferences section and can not find a dedicated "display and sound" section. I have asked Steam Support for advice (during my protracted purchase) and they do not provide me with an answer. I have found on my hard drive the SI FM15 files, created a new graphics folder and unzipped them to it as normal. Is there some restriction using Steam that doesn't allow their use? Or am I just not PC literate enough to know how to use them? Please could someone give me advice on where to go from here? Many thanks.

It should be exactly the same as FM14. I think the preferences screen looks a little bit different with the new layout, but the folder structures for logos, etc. are all the same.