Well, first you spend about 15 minutes trying to remember how to turn on the mixer (you have to loosen a nut on the thing attached to the blue thing). Then you let it mix for about 4 minutes. Next, you put whatever it is you want to deacidify in the fume hood (or spray room, if your lab is fancy like that), and just spray it evenly but quickly. If you’re doing a single sheet (like in the video), you’re done after one pass. If you’re doing a book, generally I will spray as I fan through the pages, like one does with a flipbook.
Then, voila! Your item has been deacidified. It won’t make brittle paper less brittle, but it can stop an acidic book from turning brittle.