25.

Pull and rotate it (IV quadrant) at 90 degrees so that the x-axis align exactly with the y-axis

25A.

If you are succesful, then you will have a valley fold shown on the left.

Repeat the step #25 for all four corners.

25B.

(To those who are having a problem on the step #25)

If you are puzzled at the step #25, I found a easier way to solve this problem.

On the back of the paper, draw four blue lines as shown on the left picture.

Then execute mountain-fold to all blue lines.

25C.

After you complete mountain-folding on four blue lines, you will get it exactly like the one shown on the left. This is the same picture shown on the step #28. By studying this mountain-folding of four blue-lines, you can figure it out what the alignment of the x and y-axes really means.

If you are still not satisfied from my explanation, there is one final solution. Nowdays, there are many instructional video for helping you folding a standard rose flower. Two I can find from Google search are:

http://www.youtube.com/watch?v=E72E6rqCjRU. Watch carefully on 3:30 for the step #25.

http://www.youtube.com/watch?v=BZnhMl85dq4.

26.

If you follow the step #25 correctly, then this is the same picture with a different camera angle.

That is you will have three green lines as shown in the left picture.