A sawsall (also called a reciprocating saw) would work to to cut out the interior nest boxes if there is enough room inside the coop to get your torso inside and the saw. My sawsall is probably about a foot and a half long with the blade on it I think. Personally, I would go with the jig saw again. Much smaller and easer to maneuver (sp?) in tight places. Can you figure out how the interior nest boxes are attached to the coop? Maybe you could just remove the nails or screws that they used. Don't know which might be easier.