Both firmware and midi map files are zip... your mac should be able to unzip them!?! if not you will need to find an app that will unzip them for you! Use google to locate... or the mac app store!
Once unzipped, the tsi file needs to be placed into your traktor folder, so that it can be located later when you open traktor and map the 350 using the traktor control panel - midi devices...
Not sure you will need the 350 firmware update utility - not the best thing to be tinkering with on a live stage... so id leave that one alone!
Ask the events people what FW version the 350s are at... and if possible make them update them to the latest version!