How many times have you looked over your latest kit and thought "I really wish they had molded the door handles separately"? Yeah, those molded-on handles look pretty cruddy...but they don't have to! They can actually look better than the separate, chrome-plated handles, if you have a steady hand and a bucket or two of patience. A drill bit, new #11 blade, and a little sandpaper help, too.
The main things to remember during this operation are to keep your tools at an angle that will help you avoid nicking into the door, and use as little pressure on your tools as needed to prevent flicking half the handle across the bench. Little screwups can be fixed easily enough, but cutting the handle off is a bit tougher repair that you definitely want to avoid.
Step 1 - Drill. Note the angle of the bit. You want to keep the tip from poking into the door skin on the underside of the handle.
Keep a close eye on your progress, so you can stop drilling as soon as you get through the bottom.
You want to drill your starter holes close to the body panel, but not right up to it. The starter holes make it easier to open the area with the blade, and you can shave right up to the panel at that time.
Step 2 - Score. Take the #11 blade and very carefully pull the tip along the starter holes to hog out the material between them. Please note - the angle of the knife is bad in this image. I couldn't hold it at the right angle and take the pic at the same time.
Keep working it, slowly, until you've got the area completely opened up. You're mostly concerned with how the handle looks on the top side, so do your best to get the opening accurately shaped here. The bottom is much less visible, so you can leave a bit more material down there for strength, but you still want it to be cleanly trimmed out however much extra you leave. Keep in mind, though, that one of the things that sells the look of the handle being opened up is the shadow on the door below it, so you don't want to leave too much material on the lower half.
Step 3 - Clean it up. Here's where that steady hand and a lot of patience comes into play. Slow and steady.
One of my favorite improvised tools is to take one of those one-sided Dremel sanding discs and cut it in half or a strip. The backing on them is hard enough that you get a nice, stiff sanding stick that's still really, really thin. If you don't have any of these laying around, you can also use regular sandpaper. Coat the backside with CA and trim off a piece that suits the need. Floppy sandpaper doesn't work out so well for things like this.
Final Step - Foil. I like to use two pieces of foil on these handles. I foil the bottom half first, so that I can overlap the top onto it just a little. That keeps the foil seam out of sight.
I'll come back and replace this picture once I've painted the car used to show the process, but here's a Scout II that I did last year with the same treatment. I think it makes a big difference having them opened up, not only for the accuracy when viewed from above but also for the way the shadow plays out below. Give it a try!