http://vincopoker.com/tabid/105/g/posts/t/162/Promo-di-lancio---3-mesi-da-Condor.aspx 

witch for many reasons i can't delete a make a new one, and obviously i don't want to lose people's replays and views. But still I'd like to change it from "Promo-di-lancio---3-mesi-da-Condor.aspx" into something like "AnewName.aspx".

Any how?

You need to change the topic title (Name), you wont lose anything.

The title is now different but the url did not change

Restart the Application (Admin -> Maintenance -> Restart App), and the caches will be cleared and the url changes.