The branded stuff is stored in the FS but you'll need a custpack to finalize the phone (it won't work if you flash Main and FS without finalizing). XS has a lot of custpacks for K800 integrated. Connect your phone and check the "customize filesystem" box. Go back to the "settings" tab and choose BreakXS. Then go back to the "flash" tab and check out if the custpack you need is available in the dropdown menu.