Just bought an 80-year-old Cape Cod. One corner of the foundation has settled about 5" , leaving a crack on the basement floor that extends across the floor at about a 45 degree angle from points about 10' from each side of the corner. It's also resulted in some sloped floors upstairs. I'd like to cut the foundation bolts and jack up that corner of the house to bring things into level again. The settling appears to be old and no new movement has occurred in recent years. Any suggestions on the best way to jack up the corner?