[USA in a Chevrolet]

The Dirty Blind Man sells kits with stronger strings than the original. He has a CD which shows how to restring. I believe his website is dirtyblindman.com. He is very helpful on the phone as well. As others have said it is pretty easy to do after you have done the first one. By the way, he told me the wat to make the strings last longer is to always move the shades slowly to avoid friction on the strings.