tranny fluid change

95 acheiva ,v/6 with 80,000 miles. a friend says if your gonna do it for the first time with 80,000 miles on the car, do as follows = whenever you do an oil cahnge replace about one quart of tranny fluid . that way it ain,t no severe change. he said the old tranny can,t take no severe change. he uses some kind of pump attached to a drill to suction out one quart. he is a chevy factory trained mechanic.