I have a broken retaining wall that I'd like to fix up. It's cracked, presumably from water pressure building up behind it. It's rectangular, about 13'x33', and one of the four sides is connected to the house. The wall parallel to the house's back wall is the deepest. The house is on a hill, so I figure the primary purpose of this retaining wall is to provide a flat surface adjacent to the house.

After I fix all of the drainage issues, the next step is patching up the wall.

• Could I simply replace just this one little area without knocking down the entire wall? How would I go about knocking out a small area?