If you have to teach your "tuner shop" how to do something, you're probably better off going with someone else.
As mentioned, PM someone on forums here who can help you. I can vouch for Wedge and highly recommend his skills/services.
'07 E90 335i - Automagic - Non-sport
Cobb AP|Alpina Flash|VRSF 7" FMIC|VRSF CP|TIAL BOV|cp-e DCI|Bilstein B6|E93 M3 FSB|SP Lowering Perches
Summer: Sonic Tuning ST100 - 18x8.5 ET35 - Conti DWS 245/40/18 - 10mm rear spacers
Winter: Style 159 - 17x8 ET34 - Michelin X-Ice Xi2 225/50/17 - 15mm rear spacers