Mashing is just a glorified steep. You can just steep the grains and corn in a big bag, keeping at 150 F for 45 minutes just like it says, then dunk the bag into another pot with some water, then combine all the liquid, add the malt extract, then continue the brew day as normal. Partial mash, and even all-grain BIAB, truly is as easy as that! (Just make sure the grains (not the flaked corn) are crushed/milled!)