I did this on my 68....you can see the pictures and read about it in my build thread.
Here's what I did. First, practice on a junk cab. Really, this is what I did.
On the real thing I started by cutting off a short section of the driprail about 1/4" from being "flush" and then tacked that back together in just a few spots. I did this all the way across the front. Then I came back with a grinder and ground the remaining seam back down flush with the widsheild and roof. If I remember right I also had to do a little messaging with a body hammer too.
So there is the front part.
The sides are a little easier. First, part of the drip rail is a seperate piece and tat came off, then I pretty much just cut and removed the rest, and welded it back up. Sounds pretty easy but man, some of that metal, especially around the back curve is THIN and very difficult to weld.
After I did this there was a sharp "edge" and a large gap between the door and the cab, so I took some 3/8 rod, bent it into shape and used it as a filler piece between the door and cab. This also smoothed out the sharp edge.
Good luck....lots of work!
Here are some pics:
before body work (what I did)
after body work (no paint)
