Lay a piece of masking tape across the roof in the position shown. Draw a line with a pen along the rear edge of the tape

Layout the lines shown. Solid lines indicate where you’ll cut with the razor saw. Diagonal shading indicates where you’ll remove material before reassembling the pieces. The 1/8" vertical slice shown represents a scale 3" chop.

Remove the rear window section. A razor saw is recommended for the back and the roof cuts, while a sharp X-Acto works best for the curved cut along the drip rail molding. Note the "A" is also cut at this time

Continue the cut along the drip rail forward past the "B" pillar. Cut the rear window at the bottom along the belt line. Next, remove the shaded areas on the frame. Save the piece you’ve removed.

Replace the rear window moldings on the body, lean them toward the center of the body, and trail fit the front of the roof for proper alignment. Remove the small piece of material at the tip of the arrow shown.

You may have to remove a sliver of the roofs edge to assure a flush fit. When everything fits, glue it. The portion of the chopped "B" pillar you saved earlier, is trimmed to fit the gap in the door.

Cut along the pinstriped lines to remove the rear window, *Note follow the drip rail molding in completing the cut. Then lay some 1/8" masking tape along the "A" & "C" pillars as shown, which will give you a scale 3" chop job.

Lay out lines with pinstriping tape on the "B" pillar and around the rear window. Cut the "B" pillar inside the tape, leaving a small stub of the pillar remaining on the body and roof. Save the pieces you cut away.

Cut along the upper edges of the tape to remove the roof, then cut along the lower edges and discard the four small pillar pieces. You’ll need to widen the roof at the rear to meet the body. Make a cut down the center of the roof as shown, up to within ½" of the windshield. Gently pull apart the rear roof to line up with the body.

Cut and cement a thin strip of styrene to the inside of the roof along the cut made. Fit the roof to the body to ensure proper fit at the rear where it was widened.

Reglue the roof to the body. Note the remaining "B" pillar stubs. Remove the small section of plastic at the end of the arrow to leave a smooth edge for the rear window unit. Fit the window unit, and glue it.

Using the "B" pillars you cut away earlier, fit them in place from the inside of the body, mark with your X-Acto how much material you’ll need to remove. After your cuts the pillar should look like the one shown on the left.