helped me alot in learning how to convert AG recipes to extract/partial mash. I usually convert all but 2 lbs of base malt to extract, and mash the specialty grains and adjuncts along with the 2 lbs of base malt to ensure good conversion.
The .75 conversion factor is for liquid malt extract, if you want to use dry extract you want to use .60. For instance if you want to convert 8.0 lbs of base malt (2 row, maris otter, etc):
8.0 X .75 = 6 lbs LME
8.0 X .60 = 4.8 lbs DME
I went straight from kits to partial mashing so I don't know how to convert them to steeping/extract.