Hi @davidelazzari
Here's an image from the service repair manual showing how to remove/replace the grab handle(s) in the vehicle.
Looking online it seems that the spring may not be available and that you have to replace the grab handle.
The part number may be listed on the handle itself.
It might be 3G0-857-643-B-RM5 (grey handle) or perhaps 3G0-857-643-B-82V (black handle)
[image|3683699]
(click on image to enlarge and then click on it again to enlarge further.