Replacing tub with walk in shower on concrete floor
I am in a condo with a 6 inch concrete floor and have removed the tub and notice the existing drain is a few inches off the floor whereas the drain in the shower base is about 3/4 of an inch from the floor and any drain asemblies I have seen are about 5 inches deep which means I have to cut into the concrete floor as I do not want to raise the base because it negates the benefit of a walk in shower. The drain in the base is 2 inches and the existing copper piped drain is 1 I/2 inches. Any ideas as to how I can minimize the amount of floor I have to cut out as I do not want to jeoprodize the integrity of the floor