We will send you out a cable that connects to your OBDII port and your laptop. This will enable you to read off the stock ID file and send it to our sales@eurocharged.com email along with a list of modifications on your car. We can then tune your file accordingly. Usually within 24 hours we will email back your tuned file which is then uploaded via that cable into the OBDII. All in all, a pretty painless process! Plus the tune is only $399!