Fill path to stroke in SVG

This is a dirty trick to transform your filled path to stroke in Illustrator.
This is not really accurate because it only shrink the existing path. But it do it to the extreme that you can use the stroke property to define the thickness of your design.

However, if you plan to use Vivus, you will need to know that now your paths are twice the size. So don't be surprised if the result looks awkward.

Here is the steps:
1. Select your path
2. Add a stroke to it, in a contrasted color.
3. Change the thickness of the stroke until the original path looks ultra thin. Check the angles are ok and not cut, if so change the properties of it.
4.Vectorise the stroke : Object, Path, Vectorise the stroke
5. Delete the outline of the new path. Just select an external point with the white arrow (Direct Selection tool), press delete on your keyboard (or backspace) to delete the point, then a second time to delete the entire outline. Repeat the operation for each path.
6. You can now delete the original design
7. You can now play with the new path. Make it transparent and set the desired stroke.