Use the direct select tool ( open or white arrow ) and click on the path to get the anchor points. Click on the top anchor point to move it and adjust the anchor handles to get the shape. Use the gradient tool to position ther highlight and adjust the gradient size in the gradient palette.
3. Now get the Convert Anchor Point Tool (SHIFT C), and click on the smooth anchor point. This will allow you to independently move the direction handles.
4. Now drag just the right handle downwards (see reference above)
5. Now drag just the left handle at the same angle as in reference above
6. Now drag a yellow swatch to the gradient panel to replace the orange you had
7. Now you need to position the gradient - the easiest way to do this is to go to the gradient tool (just click letter G), and you will see the following cursor change:
8. Just drag the hollow circle in the middle a little to the right and downwards to reposition the centre of your gradient. You can also adjust the slider directly if you want to increase the brightness.
Hope this helps!