That's not true - at least not in the later models, since about 2000, and I suppose depending on the company. Like bdoyledimou says below, it's just an opening underneath, like the door to putting in batteries in a toy, only you unscrew it. Pop in the memory. Just make sure you don't touch the memory with your hands. The oil from fingers can short circuit the memory. You have to wrap plastic wrap around your fingers as you slide the memory in.
OP, try crucial.com. They have some of the cheapest memory prices on the web.