The two screws that hold the adapter plate to the door are 10-32's. I made sure it was in the center (left to right) and 3 1/2" from the top. This places the hole that the wire pass's through in the area where the longer rack is.
 

I like to use a small diameter drill to pickup a center punch, like a 3/32" size. They are perfect because they will flex if you're not right in the center of your center punch. How is this a good thing, having your drill flex? That tells you if you're on center or not, even by the smallest amount. This give you the opportunity to move your work piece until the drill doesn't flex any longer, which means you're in the center. Now you can drill through with that small drill and know it's on location. Then you can use progressively larger ones to your final size, knowing that each one will follow that existing hole pretty close. Within reason of course. My final hole size was 3/8", because that's what it took to clear the connector on the wire.
 

Speaking of wires, I needed a way to keep the keypad wire from getting tangled with any moving parts so I used this wire clamp to make that happen. However, I had to open the hole in the clamp from 3/16" to 1/4" because of where I was mounting it. This clamp is made out of aluminum and drills easy, but it also bends easy too.
 

Grinding Some Welds

Now it's time to start grinding on the box. I've been wondering how this would treat me so I got prepared. I hung a tarp against my garage door to help direct most of the grinding grit to the floor. And with the use of some sawhorses and a piece of wood, I'm ready to go.
 

While I was getting my bottle of argon gas refilled at the welding shop, I told the guy what I was doing and asked his recommendation for a grinding wheel. He told me that he liked this type of flap-wheel for roughing and another type for finishing. To be honest, I've seen these wheels in stores for many years but have never used one. And I've always wondered how they worked so I gave it a try.

At first glance, they don't look like they would be rigid enough for grinding welds because of their construction. What I mean is, they are a 'flap wheel', with many pieces of... what looks like sandpaper overlapping each other. How could this last for knocking down a bunch of welds?

Well let me tell you, they work really really good. I couldn't believe how well this worked and with little effort too. Let me put it this way, if I didn't let the grinder do the work, I could easily get into trouble and remove too much material. Yes they work that good!!
 

This is what I did after about 10 minutes of work. No kidding!! It's amazing how well this wheel works. And yes I did where a mask, ear and eye protection while working. Oh, one more thing, this type of wheel is not forgiving when you touch your skin. I bumped the tip of my left index finger while the wheel was coasting down as I was checking my progress. Somehow while letting go of the grinder and moving my hand I just touched it. Let me put it this way, I'm typing this two weeks later and it still hurts. Remember, grinding wheels don't cut, they remove material, and not just metal.