if your transmission has a drain plug that has been installed by someone else then its just dropping the plug and fillin it back up,
otherwise like the rest of us, you will have to drop the transmission pan, take out two sides of bolts then just loosen off the rest starting from the two ends going to the middle. the pan will drop on an angle letting the oil out before all the bolts have to come out.
with all the oil out now would be the perfect time to replace the transmission filter, I've only ever changed a c6 filter so I don't know if there is a difference between the two setups. but the new filters have some of that info that comes with them. also the filter kit usually comes with a new transmission pan gasket which you will need anyways.
then the reverse is to put the pan on finger tight then torque the bolts evenly , doing the corners first to ensure a tight seal on the gasket.
then fill with 3/4 of the total amount of fluid needed, usually some left in torque converter that stays behind. and you don't want it over full anyways.
run the bronco warm up the engine and tranny for like a 15 to 20 min drive, then check transmission fluid level and top up if needed.
or get a shop to do it for like $40