Router on jig ready to cut.
Note a smaller unit such as a Porter Cable 690/691 would be adequate and much easier on the back!.
I use a 1/2" solid carbide end mill in the router. The end mill lasts a long time and will cut the staples with ease. These should be purchased from an industrial supply house as there, they will be ~1/2 of the price charged for a "1/2 inch Up-cut spiral carbide router bit" at a woodworking or hardware store. I paid $26 for mine at Waukesha Industrial Supply. Note this is for a replacement - the first one lasted for 7 years of furniture building, and would have gone longer if only I had plunged up before setting the router down on the concrete floor.
Also note, this is not completely operator error, as the threaded nuts visible on the left side of the router walk themselves down, and if you are not careful, will limit upward motion (no plunge up).