4. Cut plastic from inside of grill – The first cut is the point of no return - after, you're committed to finishing (or finding a new grill). The goal while cutting is to come as close as possible to the side without gouging into it. Trust me, it is much easier to grind and sand away a bit of excess than to fill the gouge and sand it. I used a Dremel with a cutting bit as shown. If you go this route, I strongly suggest earplugs as it makes a very high-pitched, piercing noise that just may cleave your skull in half if you hear it long enough. :-O

The patient, front and back views:





First cut, of many:



Success. You can trash this piece, then brush off all the little specks of black plastic from your arms. :-)



Here's what you should end up with:



5. Sand the inside smooth - Each of the black spots is an attach point that’s been cut away. Here you can see what I mean about not gouging those spots. I had to fill and sand several, which added an unwelcome and unnecessary layer of time and aggravation. Note gap on side where the large middle piece shown in the pic above was attached. There’s a similar gap on top. We’ll take care of those next.

Note the chrome isn't taped yet but definitely should be.