Once the inner bracing was in place, I started finalizing the exact placement of the cuts to be made.

This masking tape is 1 7/8" wide. Add a sixteenth on top and bottom for the saw blade, and it will be a 2" chop.

For the side window, I picked a spot as low as possible so the top would come straight down onto the bottom section. This will minimize the metal shaping work to get the window curves right. The body metal is nearly perfectly straight up and down right next to the window, but as you move around the back side of the car, the metal starts to taper up. The tape line was moved down as far as possible where the roof curviture radius was minimized.

As the tape wraps around the back of the car in a level horizontal line, you can see it getting closer to the body lines. I don't like the look of the mail slot rear windows, so another vertical line will be cut so that 1 inch can be cut out through the rear window, and 1 inch will be cut from below the rear window. This will improve the proportions of the windows because the rear window is about 2 1/2" above the body moulding that wraps around the car, but the side windows are only 1 inch above that line.

Lowering the entire window opening 1 inch will help it match the look of the side windows, while still giving enough room to see out the rear view mirror. The vertical cut lines will help with aligning the long horizontal cuts.

For me, the most difficult part of the planning stage was marking out the front windshield posts. Since they slant back slightly, I can't just lay on the masking tape. 2" wide tape at an angle will not equal a 2" vertical drop.

First I found a good spot for the bottom cut line. Then I held some posterboard against the front of the windshield at the bottom cut line, and used a level to draw a line straight up. I used a tape measure to mark off 2" on that vertical line, then used a square to draw a 90 degree angle line horizontally back to the edge of the paper. The spot where that line touches the windshield frame is the top cut line.

Then there's the trick of drawing a level horizontal line all the way around the post for the top and bottom cuts. I just used a short level to very carefully mark all the way around, an inch at a time. I had to erase the black line a couple times, but it was worth the time and effort to get it right. Anyone know of an easier way to mark the windshield posts?

This spot on the B pillar was chosen because, over a 2 inch wide space, it was perfectly stright up and down. The top cut line should line up exactly on top of the bottom of the post after being cut. The same is true for the C pillar, where the rear door hinges are located.

One more shot of the original top before cutting. At this stage, all the cut lines are taped off, checked, double checked, and re-triple checked to make sure I wasn't forgetting anything. All the measuring and taping was a full day's work, but I allowed several days for the double checking process. I tried not to get in a hurry at this point. Every time I look at it, I think of something else that might be an issue.

One last shot around the back corner. Everything looks good.