The radiator support is an intregral part of the front uni-body structure. The old support needs to be cut off and the new one welded in. However, it's very important that everything aligns properly. All your front sheetmetal alignment depends on it! IMHO the best/cheapest course of action would be to strip all the front sheetmetal, radiator, accessories, etc, bring the car to a reputable body shop and let them do the install. It'll save you countless headaches later! Here's a pic with frontend stripped.
http://img.photobucket.com/albums/v3...71_90_full.jpg