Hello @Dimitris1,
Don't remove your current ID yourself as the help section on ID says that your upcoming reservations will be cancelled if you remove your ID photo.
The biggest benefit of uploading ID is not the ID itself but the fact that a host was willing to do it.
Guests never see your ID but they can be happier with a host when they see that a host is ID verified.
Airbnb will still be able to hand your old ID information to authorities if there is a problem so I wouldn't be worried about updating it on the site.
If you really do wish to update it you should contact Airbnb customer support.
Click on "Help" and then on "Visit the help centre" and then on "Contact us" for ways to do that.
http://www.airbnb.com/help/article/1237
this article says:
Updating or removing your photos
90 days after you complete your most recent booking, you can remove your government ID photo by visiting your Edit Profile page. If you remove your ID photo, any upcoming reservations will be canceled.