Before your question can be answered properly, tell me what kind of surface material you're working with. Wood siding, aluminum siding, cedar shakes, masonary etc. For now I'm going to assume, wood siding and/or masonary. Actually there is no need to strip it. Scraping the loose paint and sanding with an 80 grit paper and palm sander to feather out the rough spots is all you need to do. Don't forget. Those layers of paint are also a little added protection for the surface. A paint gun can be helpful. I've found that just taking my time, not busting my butt and preparing and painting a section at a time, (front of the house, then the side, then the back etc), may take me 4 or five weekends but, I'm in no hurry and I see results each time. If you feel you really want to strip it, there are two alternatives. Chemical (including soda-blasting) paint removal from hard or soft surfaces, including wood, brick, and metal surfaces. It's safe and non-destructive. There is also water pressure. Some reach up to 10,000 psi for paint removal from steel or concrete. But unless you know what your doing, mask and cover all your windows, doors, selected trim and flora, this is best left to professionals. Hope this helps.