Andy,
Alfred's links above are critical to read.
The correct lower clips are essential to hold the aluminum moldings on. The key issue is to match the thicker aluminum doors to the right reveal on the clip. I believe there are 7 clips per side on each door, which means you need 14 yellow clips (or clear ones, if the old ones still have wings, and the plugs aren't cracked or brittle, which happens all the time). The little white plugs are also critical (which you push in after the clip is in the hole with a nail set), so I would not avoid them. Finally, don't forget to mount at least two metal pointy spring clips on each door between the white plug and the clip, as the doors closing all the time tend to want to shift the molding, which will create a nightmare if they slide too far.
The steel is much thinner than the aluminum, so you have to use the blue clips on the 2 lower moldings that are not on the doors. I'd use the blue clips. All the clips regardless of color should have wings and the wings should be mounted vertically. When you put the molding on, try to slide it onto the pointy metal clips from the side and the top, and once tight to the body on the top, just give i rap with your palm all along the bottom, and it should click in. The aluminum moldings dent, so be careful, and don't use a tool.
Hope this helps.
Mike Mizesko
Columbus, OH
