You can check out Instructables for the full list of instructions, but basically the whole process involves building a stand with plexiglass slides, then backlighting those slides with an LED. A lens from a laser pointer does the magnifying. The magnification on the DIY 'scope goes up to 175x, which isn't half bad--enough for some simple DIY experiments, at least. Judging from the video, it works better than you'd think. Wonder if you can diagnose malaria with it.