Before ordering 034Motorsport Motronic Audi I5 software, you must make sure you're ordering correct software - which solves lots of problems down the line. Audi has two distributorless 20vt ECU's that are pin for pin compatible with each other, but very slightly different internally. The ECU found in the RS2 is unique, the rest of the 20vt line up is, for all intents and purposes, directly interchangeable.
So, easy enough, there's not that many RS2 boxes out there, right? Wrong, it was/is common practice for some tuners to reconfigure a 'normal' 20vt ECU to be able to properly use their RS2 software, so rather than writing new code twice, a hardware change was done.
This modification needs to be checked for before ordering new software for that ECU to ensure you're getting the matched configuration. Thankfully doing this is simple. You'll need a multimeter set to measure resistance (Ohms). And you're going to want to measure between pins 7 and 25 on the ECU. Here's a graphic to help you track down the proper pins:
With a standard, non RS2 ECU the multimeter should read ~19.38k, an RS2 configured ecu will read ~18.77k.
Now that you know what ECU configuration you have you will want to open up the case by prying open the metal tabs around the base and lifting the top off. You'll also have to pull the plastic inserts out of the plastic posts that hold the ECU circuit boards together. Once these are out/off pop the rear end of the ECU apart from the bottom board, while this is tilted upwards unlock the two side tabs in the ECU connector to completely unlock the ECU halves and let it open up.
If the ECU has never been modified the stock chips will be soldered to the board. Take the ECU to a professional installer to have the stock chips removed safely from your board and have sockets installed (034Motorsport can perform this for you as well).
Now, with a socketed ECU install the new chips as shown, they will be labeled 'FUEL' or 'BOOST', and are installed in the positions noted below:
In this case this code is for a 3071 turbo with a RS2 ECU, Stage 1 software, pump fuel, software revision 2.