The basic idea is switch the fates of Germany and Italy.
Germany falls into many city states and is subject to foreign influence, those powers could be France, any nordic power, the plc and the HRItaly (note that Austria and the Netherlands are included in the "Germany").
Italy forms the Holy Roman Empire is able to resist foreign influence (at least for a while), falls into many inner wars, and is dominated by one family (Medicis?)
Your job is to find out what's plausible and is likely gonna happen.