Page 13-6 of the Shop manuel shows just exactly what you are dealing with.
If you want your stock bar to remain prestine, carefully put it in a padded vice. You could take a piece of pine, bore a hole thru it, cut the wood in half, and go that route. Whatever route you go, you need that thing held down TIGHT! Now, take a 1/2" thick piece of oak or maybe a length of angle iron aprox 18' long, drill a 1/4" hole in the center. Take your handlebar weight off. Using your weight screw, attach your length of wood to the handlebar weight. Now you have something substantual to pull with. I recently took the weights out of the clip-ons of my 929 so I could put on HeliBars. I'm guessing it took aprox 150 lbs of pull to get those things out. Maybe get a buddy to help.
In your case maybe you could attach a piece of wood to both weights and stand on one and pull on the other. Like I said, it takes a good deal of pull to get them out, don't wreck your back.