A5 PATTERN PIECE 1

Each pattern piece is clearly labeled. Open your pattern and find pattern piece one. Cut it out.

Then lay it atop your man shirt. Get the corner marked 1 as close to the arm pit seam marked 2 without crossing over the seam. Also, be sure that the shoulder seam of your pattern does not cross the shoulder seam of your shirt.
Be sure to line the edge of the pattern up with the edge of the shirt. Pin it down.