You can patch two ways.
1. new optionfile
2. complete patch
1. is easy you only have to swap one file
2. this give more editing options (new stadiums), but is a little more complicated. But with a little help and following the readme strict there should be no problems
At the moment I use the powerpatch. It's a complete patch (kits, boots, balls, ad-boards, stadiums etc.
With it you get 2 movies how to install so it's not to hard.
Search the forum for more info, I will post the download link later (if you can't find it).
Grtz,