Stage 3 - Now you will make a valley fold. Where the corners of the flaps you just folded meet, you need to fold over the topmost tip down to meet at that point and then carefully crease and flatten down.
Stage 4 - Working with the same tip, fold it back over a short distance so it points upwards again, the distance isn't important, but about an inch or an inch and a half and crease again at this point and flatten down.Throughout these folds, be sure you have folded them so that the central crease lines up otherwise your next move will not work very well.
Stage 5 - Now, mountain fold your work along the central crease, effectively folding the piece in half.
Stage 6 - Important, with your crease uppermost in your hands and the thiiner end of the wedge shape between the thumb and finger of your left hand, take hold of the point of the small wedge on the upper edge of the crease and lift it a short way so there is a gap of maybe 1cm or so and pinch the make your new crease to hold it in position. Now you will have a triangular wedge pointing out at an angle of about 35 degrees from the rest of the work.
Stage 7 - Your next move is to almost the same move, but this time with the left hand and with the larger wedge under the small one you just lifted. Just take hold of the point you just worked with and gently lift and pull out to your left while holding the rest steady with your right thumb and finger. You will see the lower edges begin to flay out - keep going until you have moved the thicker wedge thru to about 60 or so degrees and then pinch the lower edges to make new creases and hold the thicker wedge in it's new position.
Your job is complete - simple!