Can't override the soft limit when calibrating

Anyone know how to override the soft limit to move the bit so I can finish calibrating? I'm trying to zero my "Z" axis. I'm sure it's operator error. I got the up/down movement accurate and accidently click the "Zero" button before getting the bit down to the stock. Now it won't let me move the bit any lower. I can move it up and then back down, but not past that last point. I've tried resetting but so far, nothing has worked.