How simple is the transmission filter on a 1991 Mitsubishi 3000GT SL., changing of., do it yourself or suggest taking it in.?

have to drain the oil undo 18 or so bolts undo the filter place the gasket, then tighen it gradually to 13 ft lbs, top to the line with new ATF...yeah scurryin' around on your back for half the day...are you sure?? a mechanic with an overhead lift can do it, dispose of the old oil and you won't have to scrunch down like an educated chimp....in short, just take it somewhere. we know how much it should be-