Start by hammering a line about 16 in. to eighteen in. away from the wall. Start off by chipping within a straight line together all the size in the wall, then come back and bust it into workable chunks.  Basement Gurus is happy for being detailed on every one of these websites https://basement-waterproofing-yo44320.blogtov.com/15943194/considerations-to-know-about-basement-waterproofing