what litre fofo u got? i got a 1.8 and just got a 2.l throttle body and MAF... should i see a difference
when i ported out my IM, i stuck a rag or 2 in the hole (so nothing gets in there) then used the bracket that comes with the TB to trace an out line, of how big it was, with a silver sharpie (so i could see it). I used a dremmel (AC power) to slowly bore it out. Take your time doing it, try to have smooth edges, and stay within the sharpie marking.
mlbbaseball told me to take it all off then do it then soak it in water and blow it out with an air compressor, but i didn't have the time so i didn't. But it is a good idea to do it that way to make sure nothing like plastic or dirt gets into your engine.