Here's how it's done.
I used a Towing Mirror kit from Autobarn, cost me $35.00.
First I flattened the shorter end in a vice, you need an extension on the vice handle as the arms are steel and pretty tough. I also added a bit more to the angle of the bend, so they wouldn't stick up too high when mounted.
Then, work out where you want to place them, there are several options with the screws on the windshield brackets. The bolts are 5/16 UNC. I used some cap head screws I found at Repco. I also glued some 2mm rubber on the back to protect the paint when mounted.
Then I put the mirror on and checked to see how far out they needed to be before cutting the excess off.
Anyway, it wasn't too hard to do.