Fabia 1.2 EGR cleaning

Started to clean my gf's egr on Fabia 1.2 HTP and the nuts were so badly rusted that one of the studs broke and had to take it engineering comp. to drill it out. It broke right at the adapter btw engine block and the egr. Got stainless steel long M8 bolt and trying to put all back together after i've fnishe cleaning.

So im hearing that you have to reset values after you reassemble the egr??? I have VCDS Lite software for checking faults etc. and have the vagcom cable ... Is it wise thing to do it myself or is it better to take her to garage for that matter. They charge 50 eur for even switching off the engine light. Robbin' f=====. thats in advanced pitstop. Any suggestions???