Ford Escape Crossover sub Frame replacement

Why because it's rusted out ? If that's the reason the rest of the car is also , The whole assembly , motor and tranny ,would probably drop down with the sub frame .

Chevy is right, it's not worth the time and effort. The Escapes of that era are known to rust fast if you live in the rest belt. Look in the rear passenger side wheel well, remove the interior panel, you probably can see daylight through to the tire.