wow - I have heard of people not searching the forums, this is the first time I heard of someone not believing them, lol.
yes you can really change your second profesion after you ascend (some people say before you ascend, but I have never had any of the quest givers talk to me before I ascend). And before you ask, yes it is true that you can change your second profession as many times as you want, and no you do not keep the skills availabe to use from the profession you just got rid of, but you do get them back if you change back to that profession.
there are 3 towns in the desert that have nothing to do with ascension missions, find them, in each town is one or two people that give the profession quests, each person is to change to a diffrent secondary, so find the one you want.