When I last replaced my windscreen wiper blades, I put the old ones in the bin, but I knew they wouldn't stay there long. Sure enough I had this simple idea. When I replaced them on my new car, I decided to do the same and take some photos while I was at it.
Pair of old windscreen wiper blades
Steel wire (not stranded)
Step 1: Take the rubbers out
Just pull them out, the metal strips too. Simple as.
The metal strips could possibly be used instead of the steel wire later.