Sorry, it's been a while since I flew my drone. I just powered it on and I see they made a change to how it works in this last update. You can turn off the flight limit completely, but you can't set it to a new setting.
To do that, once your controller has connected to the Karma, swipe up so you're looking at the view through the camera. Touch the graphic in the lower left corner. That will bring up a menu. Touch Flight Limits -> Maximum Altitude. In the lower left corner, touch Flight Limit On and it will toggle it to off. Now, there is no flight limit.