What you need to do is right-click on the file named "A3ManiaClient.7z", select 7-zip> Open Archive and extract the files where you want to.
I've compiled this little mini-guide-ish thingy to guide you:
1. You first have to right click this file right here.
2. Then you select 7-zip> Open archive.
3. Extract it to your desired location.
4. The last thing to do, is apply the patch to that specific location.
And that's pretty much it, I guess.