I have a 170 year old brick house on a cobblestone foundation. Some of the floor joists and sills have dry rot and powder post beetle damage. While the joists are relatively easy to repair, I am at a loss as to how to best repair the sills as they are grouted into the foundation and the joists which are resting on them have crushed them down substantially. The basement has a dirt floor and limited headroom, so it is not real easy to bring in equipment.

Any suggestions on how to best repair the sills?