All you'll need is the bar with grills attached, may need to bring over fog lights if you have them and the new bar doesn't and make sure the lips are the same. The bars changed as part of the series changeover in 2005/6 - The early twin grill came in both a long and snub nose style and both with lips that are possibly diferent, so just be aware of that. All bars mount up the same, the only difference is how they look.
Note also that the FOG LIGHTS are incompatible between the two bumpers. If you look closely you will notice the blue car's has perpendicular inner sides where as the blue car's are on a slant. The are available however on ebay for under $200.