I just did this to mine....matched ported the inlets and turbo flanges..and even done the metal HKS gaskets...was easy when taking the turbos off the carbon deposit that was left on the manifolds and gaskets pretty much outlined it all.
I used a dremal with a tungston carbide tip that was alot better that the grinding stones that you can get from supercheap, which are no use at all.
Found a store at minto, that sell only abrasives..got the proper grinding stones and the tungston tip from there...$3 for stones...and $15 for the tip.....the stones last a very long time and are the proper ones to get.3mm size shanks.
too bad only just read this, i have just finished putting back my turbos. could have taken some pics.