I learned by trial and error. Now I know the trick to getting the dash in and out so I can do it pretty quickly. For the rodeo, the bottom unit is the same as the top unit, with the exception of it having a seporate piece of plastic surounding it that simply snaps in with friction tabs (springy metal on each side of a piece of plastic). What I would suggest, is getting a Haynes or Chiltons manual from any Auto Parts store as a reference. It'll tell you where all of the screws are, and any steps that aren't obvious you might miss..