I have a basement stairwell which is protected by an 8 foot cinder block wall. There is a crack in the wall which is getting bigger. I have taken some corrective measures to fix the drainage since the back yard slopes into the house and against this wall. The crack in the cinder block in as wide as 2" at the top of the wall and goes down 6' of the 8' height. How can I repair this with out digging out 8'(height) of earth around the wall?