Jeep: Cherokee- convert standard tranny to auto

I want to convert my '92 Cherokee 4.0 2wd 5 speed to a 4wd auto. I
already have the donor vehicle, an 89-91 Pioneer 4x4 with a 4.0, not
sure of year (which runs but needs underbody work). How hard would this
be? Is it possible as far as the electronics go?

Thanks