An ice chest/cooler will substitute nicely for the cardboard box you’ll need to collect up the parts she’ll deposit on the pavement.
The thought has occurred to me that the old 3 speed might not survive. I figure low range would be safe enough for a few tests.
Jeeps like mine are dual lever transfer cases. I can get low range and not engage the front shaft.
Reman transmissions for mine are available for about grand.