Seems like building a solar shield to reduce incoming light would be the simplest approach.
Besides, once you've got the technology and materials to build a solar shield which is an appreciable fraction of planet-sized, you might be questioning whether a planet is really the best place to live. Why not just live in your giant space stations?
If you look at the Day/Night cycle on earth 1 week without sunlight would probably drop Venus into sub zero temperatures. Depending on how much over kill you provided a few months would be plenty of time to cool down to reasonable levels.
Per unit surface area, how much less sunlight do you get at Earth's poles than at Earth's equator? That's too hard for me to figure out off the top of my head (taking the seasons into account), but I'm pretty sure it's at least a factor of two. So I think a planet with an Earthlike atmosphere in a Venusian orbit would be habitable in the polar regions.
However, the atmospheric pressure at the planet's surface is 92 times that of the Earth. So the difference in temperature in the summer is far less than the earth because a lot more energy is transferred to the poles. If you where to somehow remove that atmosphere not just change it's composition the poles may just barely become habitable.
Also wind speed is temperature dependent (Wind being a heat engine) so even with earths atmosphere a lot more energy would make it to the poles in summer.
There is already a crap-ton of SO2 in Venus's atmosphere (about 40 teratonnes, to be precise), that's where the sulfuric acid clouds come from. If we sent a supertanker full of SO2 to Venus every single day for a thousand years we wouldn't affect the amount of SO2 in the atmosphere by even 1%.