oh its easy. First, the top of grain bins are litterally clamped on, simply remove top, insert tub, clamp to back on. What the people building them into houses do most of the time is have it welded shut, I wouldn't. It's already air/wet tight with the giant clamps and it's double hull, unless you take a direct hit from a tornado, it ain't coming off. and even still, I've seen tornadoes hit them and the tops stay on and the bin sheer in half.