An interesting question to be sure. However, the ramifications of affecting history is too great. I would rather do the following:
1. Visit Giordano Bruno the night before his execution and tell him that, even though he will die in the morning, he was right about the stars.
2. have a chat with Galileo regarding what we know about planetary physics.
3. Give Leonardo a ride in an airplane.
4. Tell Kepler to give up the whole regular solids system for planetary motion.