Welcome! You can read and post your tune. I'm not sure we'll be able to make much sense of it, but we can try. You'll probably end up starting from scratch like I did, it's easier in the end.
Read this to get started and familiar with the tools/software you'll need:
http://www.nefariousmotorsports.com/wiki/index.php/Getting_StartedThen read Nye's tuning wiki article to familiarize yourself.
http://s4wiki.com/wiki/TuningStart with a stock M box file.
MAF scaling:
I have an 83mm RS4 MAF housing and originally attempted to scale the stock MLHFM MAP by calculating a correction factor:
73mm (stock MAF housing) / 83 (RS4 housing) = 0.8795
I then multiplied all of MLHFM by 0.8795. This worked ok, but my AFR would vary between gears.
So I redid the MLHFM by scaling from Tony@Nefmoto's 85mm MAF housing file. Copy Tony's MLHFM then calculate the correction:
85mm (stock MAF housing) / 83 (RS4 housing) = 1.024
Then multiply the whole table by a correction. This seemed to work better for me. You will calculate using 90 instead of 83, obviously. Try either of these routes and see how they work for you. I still have a stock KFKHFM MAF correction table.
Injector scaling:
You will want to get the datasheet for your injectors, if possible. You will need to edit KRKTE and maybe TVUB.
There is a calculation for KRKTE although a few of us have kind of just been estimating it and altering the value based on LTFTs. My gasoline 60lb Deka @ 3 bar KRKTE was 0.101, for reference.
My 1000cc EV14s came with a datasheet. I used the dead time specs for TVUB. When I had 60lb Dekas I used a stock TVUB.