errr, to remove square taper cranks you need a crank extractor tool.......if however the threads in the crank to be removed are stripped, you need................................an angle grinder :twisted:
just cut through the BB to remove the crank from the bike and then the BB can be removed as per normal...........I've had to do it a couple of times on some 'quality' purchases that came with 'cranks included' :roll: