"Beg, borrow or steal. I'm your Huckleberry"
You can get those manual screwdrivers at just about any hardware store. If you can't find it at a big-box "Home Improvement" store check your local mom'n'pop.
Actually, check your local mom'n'pop first. Also, pick up a hand-cranked drill. For some reason I keep finding uses for such an archaic device.