This notes are dedicated for every update action

1. disable the system in CONFIG/SYSTEM section
2. copy all files from archive into your sls root directory
3. run update.php script
4. If you have own css style file, compare it with original.css (or gtrpl.css) to find diffrences
5. enable the system in CONFIG/SYSTEM section

In case of troubles check support forum: 
http://simracing.pl/forum/f115/