Hi I tried to draw the block on EQ7 but with dealing with a 6.5" block, I figured that the 4 patch in the center measures 2 7/16 finished. You could make them 3". I would then undo the a stitch on both seams to open up the center. (Eleanor Burns technique) Press it so it is flat as a pancake and then using a glue stick place it in the center. Has to be exact otherwise it could look crooked.
You can always increase the size of the block to make it easier. Good Luck. This is not an easy PP pattern to have as your first project.