Hi,you're kinda new, i guess. Welcome.
1.In order to have all the jams (textures) , you must also download the 2012 tracks,this means the first release and the updated trackpack.
Or if you have the 2012mod installed, you only need the updated pack.
The start of the 2012 season is on grandprix3.co.uk, the rest is on this site.
2.In the 2012 tracks, there is a little manual to guide you for installing the track and textures; do this for 2012 and 2011 files.
If you have installed it properly you now have the 2011 and 2012 season.
3.You must have the NoCD-patch 1.13 installed
4.You must have GPxPatch installed and run it in debug mode with low verbosity
If this still sounds like chinese, send me a private message with your email and I'll make you a detailed step by step guide.
Dirk