Yes you can. You need to be on the main screen(not the Detail screen) and click on a villager. After you have him/her selected and the white circle is around their feet, you can hit the F6 key. This will not work,however, if the villager you want to change is wearing the last outfit choice available. So, if you try it and it does not change, then your villager is stuck with that set of clothes. You may have to try a couple different villagers but it does work. Most of the time I leave my people the way they are unless I get too many wearing the same thing and can't tell them apart lol.
Hope that helps. Someone a while back actually went to the trouble of listing the outfits for men and ladies, even with pictures! That thread had detailed instructions on how it all works, but I don't know where to find it. Maybe someone more experienced with forums can help find the link and post it for you.