The basement is 50 year old poured concrete with a steel hopper windows.

As far as I can tell these are just held in with cement grout. And that I need to chip the grout out. I know that I can sawzall/crowbar the old frame out, but I still need to do the chipping to get a clean area for the new window.

The opening appears to be about 31 1/2″, but I can tell for sure until I have cleaned out the old one.

I have found a local company (Columbia Windows) that has 31″ wide slider and Do-it-Best (Dro-Corp) that has 31 3/4″ wide units.

Is it as easy (expect for the chipping) as this or am I missing something in the way that the old windows where installed.